We are going to study the chemistry involved in the formation of a triple bond. Examine by studying the appropriate triple bond examples of alkynes, functional groups, etc.
Lets have a look at various tripe bond examples :
So what is a triple bond? When atoms share three pairs of electrons and form a bond the resultant is a triple bond. It is said to be highly reactive with low or shorter bond length. The triple bond is represented by three parallel dashes (C≡C ). They are observed to have low melting and boiling point.
Also, it is considered that as the number of carbon increases, the melting and boiling point also increases; they are soluble in organic solvents and insoluble in water. So we will have a closer approach to the formation of the triple bond by studying molecules of various triple bond examples.
Strength of Bond: As the strength of the bond increases, the length of the bond decreases. Triple bonds are much stronger also shorter than double bonds between the same kind of atoms. The bond length is around 1.203 Å, and the energy required to break the bond is -365 kJ/mol. Bond length is observed to be inversely proportional to bond strength and bond dissociation energy.
The concept of hybridization is very useful in understanding the concept of shape and molecular geometry of molecules. So the hybridization is the intermixing of atomic orbitals leading to the formation of the desired new hybrid orbital. The sigma bond is formed between the sp orbital of the one-carbon with that of the sp orbital of the other carbon. Pi bond formation takes place between the p-orbital of the two carbon atoms. So we shall apply this concept in understanding various triple bond examples.
Triple bond examples
1. Acetylene
It is considered as the most simplest hydrocarbon containing the triple bond CH≡CH, one sigma + two pi bonds. It is a tetravalent compound with valency-4. We know that carbon and hydrogen are involved in the formation of acetylene. So the atomic number of carbon is 6, its valency is four, meaning the number of electrons available for bond formation. This are very common triple bond examples .
Hydrogen with atomic number 1 can share its electron for bond formation. So in the acetylene molecule C2H2, two carbon atoms and two hydrogen atoms combine together.
The type of hybridization associated with acetylene ( ethyne ) is sp, meaning it has half s – character and half p – character, has a bond angle of 180 degrees, and possesses linear geometry. It is observed that the electronic configuration of carbon in the ground state is 1s2 2s2 2px1 2py1, so there are only two electrons that are unpared, but carbons valency is 4.
So for bond formation, it requires 4 electrons. Therefore 2 electrons from s orbitals go to 2pz orbital, which is empty during the excited state. So during the excited state now the carbons electronic configuration becomes 1s2 2s1 2px1 2py1 2pz1.
Every atom of carbon hybridizes by sp hybridization of 2s and 2p orbitals during excited state giving two half-filled orbitals ( sp ) having a liner arrangement.
2.Carbon monoxide :
A triple bond is found between a carbon atom and an oxygen atom. It consists of 1 sigma and 2 pi bonds. It is said that carbon monoxide has the strongest covalent bond. The bond formation between carbon and oxygen takes place by covalent bonding, i.e., sharing of electrons between 2 atoms ( carbon, oxygen ).
When the carbon atom obtains the lone pair from the oxygen electron, the resultant bond is non-covalent. So 2 are covalent bonds, and 1 is non-covalent bond. The bond order is found out to be 3.
The valence electron in carbon is 4 and in oxygen is 6. It becomes much more easier to determine hybridization if we know the steric number of the molecule ( steric number – is said to be the number of pairs of lone pairs around the central atom ). It is observed that the molecules which have 2 as the steric number, the hybridization is said to be sp.
The C-O sigma bond results from 2pz orbital of carbon and 2pz orbital of oxygen overlapping. Out of two pi bonds, one pi bond results from 2px orbital of carbon and 2px orbital of oxygen overlapping, and the second pi bond results from 2py orbital of carbon and 2py orbital of oxygen overlapping.
It is a molecule in which covalent bonding is between 2 carbon atoms. So basically, propyne is made up of 3 atoms of carbon and 4 atoms of hydrogen. The first carbon is bonded to one hydrogen by a single bond and attached to the next carbon by a triple bond. And the second carbon is attached to 1 carbon by triple bond and another carbon by a single bond.
The third carbon bond is attached with 3 hydrogen atoms by a single bond. So, therefore, it has 6 sigma and 2 pi bonds. The melting point of propyne is negative 104 degrees Celsius and the boiling point 23.1 degrees Celsius. It is observed that it is insoluble in H2O but is found to be soluble in chloroform, benzyne, etc.
As we know that there are 3 carbons in the structure of propyne; considering the first carbon, it has two atoms attached to it, one of carbon and the other of hydrogen. So there is no lone pair around the first carbon atom. Hence its hybridization is observed to be sp.
Taking into account the second carbon, it is attached to 2 carbon atoms on either side, and no lone pair exists. Therefore its hybridization is sp. Now referring to the third carbon atom, it is attached to 4 atoms, out of which three are hydrogen atoms, and one is a carbon atom, and no lone pair is present, so the hybridization of the carbon is sp3.
4. Benzyne
It is an example of an aryne tripe bond. It is a very reactive intermediate. We can consider this as an exception because the second pi bonding is a result of the weak interaction of sp2 orbitals (hybrid), which is in the rings plane.
Benzyne structure ( rare case of triple bond example)
The formed triple bond is found to be non-linear in nature due to the strain and reactivity (relatively high ) of the 6-membered aromatic ring. It consists of two sigma bonds ( sp-sp ) and one pi bond (p-p ).
Hybridization: It has been observed that the carbons having triple bonds are sp hybridized, and the remaining four carbons bonded, which are single-bonded, are sp2 hybridized. Benzyne are rare kind of triple bond examples.
Its chemical formula is C4H6 with melting -32 degrees Celsius and melting point 27 degrees Celsius. Its synonym is Dimethylacetylene. There are nine sigma bonds and two pi bonds in the molecule. The first and the fourth carbon have 4 sigma bonds, and hence it is sp3 hybridized.
Its symbol is N, and the atomic number is observed to be 7 and belongs to group 5. It mostly exists in a gaseous state with a melting point of -209.86 degrees Celsius and a boiling point of -195.795 degrees Celsius. The valence electrons in Nitrogen are five, so in order to complete its octet, it needs more than three electrons.
Therefore it shares its three electrons with one more Nitrogen atom to satisfy the octet rule. In N2, there is one sigma bond and 2 pi bonds. There is one lone pair present on the N atom. The steric factor in Nitrogen is said to be 1 + 1 = 2. The bond angle in N2 is found to be 180 degrees with linear molecular geometry, and its popularity is observed to be non – polar.
The electronic configuration of N2 is 1s2 2s2 2px 2py 2pz, 3 of the 2p orbitals are left empty. So these half-filled 2p orbitals take part in the bonding. So these three half-filled orbitals from each of the Nitrogen overlap along the axis ( internuclear ) for bond formation. Thus the triple bond between the 2 nitrogen atoms is formed. This N2 is very important for organisms. It is also used in various industries for the manufacturing of fertilizers etc.
FAQs
1. Is F2 a triple bond?
No, Fluorine does not have a triple bond.
F2 is said to have a pure covalent bond. The atomic number of fluorine is said to be 9, and the electronic configuration is 1s2 2s2 2px2 2py2 2pz1. So the number of valence electrons is 7. To achievea complete octet, it needs one more electron.
It combines with one more fluorine atom and completes its octet. Bonding occurs between 2pz of one fluorine atom and 2pz of 2nd fluorine atom, and the resultant is a covalent bond. There are 3 lone pairs of electrons on the F1 atom ( each ).
2. Is H2 a triple bond?
No, H2 does not have a triple bond.
It forms a bond by single bond formation. As we know that its atom is a non-metal, so H2 (molecule) bond formation will be covalent. It is also observed to be a non-polar (covalent) bond as the bond formation takes place between the same atoms, therefore there is no difference in their electronegativity, in other words, what it means is that the atoms of hydrogen and electrons are equally shared.
Its melting point is -259.9 degrees Celsius, and its boiling point is observed at -252.8 degrees Celsius. It is considered the most lightest of all the elements. It is quite stable but still is capable of forming various bonds. It has three isotopes, Tritium, Deuterium, and Protium, and all of the three have variations in their properties.
H2 is found to be inflammable (highly) and can catch fire in the atmosphere if it encounters the required conditions.
If we speak about hybridization, there is no hybridization in hydrogen as it has only one electron, so logically it is not possible to mix the orbitals and form hybrid orbitals.
3. Is HCN a triple bond?
Yes, HCN (hydrogen cyanide) has a triple bond (between carbon and nitrogen atom).
It is found to be hazardous. So while working with, it one must be very careful. It can exist in liquid or gaseous form.
The melting point is -13.29 degrees Celsius and, the boiling point is 26 degrees Celsius. The HC-N molecule has a linear geometry. Hydrogen cyanide is a weak acid; it can ionize partially in the presence of water, resulting in an anion of CN−. Thus hydrocyanic acid is formed. It is used in the mining industry for gold and silver mining.
Also, many important organic compounds are prepared using HCN like EDTA, adiponitrile (it is a precursor for Nylon -6,6.) Hydrogen cyanide consists of three atoms (one hydrogen, one carbon, and one Nitrogen). The bond between carbon and hydrogen is single, while the bond between carbon and Nitrogen is triple. The steric number is found out to be 2.
The hydrogen in this molecule is not having any hybridization as the one hydrogen electron is bonded with one carbon electron, thus satisfying its valency. The hybridization of carbon in the molecule is sp .
Fungi are typically a group of eukaryotic unicellular or multicellular spore developing heterotrophic organisms. More than about 148,000 fungi species are present throughout the world.
Let’s discuss about some eukaryotic fungi examples with their features respectively.
Let’s have a closer look to these eukaryotic fungi examples respectively-
Mushrooms
Mushrooms are refers to a group of fungi species bearing umbrella shaped fruiting bodies. They are mostly macroscopic and grow on soil or on its own nutritional source. They typically have a stipe (stem), a pileus (cap) and gills. Some examples of mushrooms are Agaricus bisporus, Agaricus campestris, etc.
Yeasts
Yeast are single celled fungi species having ability to adapt multicellular characteristics during adverse situations. They are typically small in size (about 3–4 µm in diameter). Yeast are generally found in sugar rich environments like on the skin of fruits, on flower’s nectar. Sachharomysis cerevisiae is one of the largly used yeast species for fermatation process.
Molds
Molds are groups of multicellular filamentous fungi species having thread like filaments (hyphae). The network of hyphae makes mycelium. Molds reproduce by conidia formation from the end tip hyphae. Aspergillus niger, Aspergillus flavus are examples of some most common mold species.
Rusts
Rusts are obligated parasites, highly pathogenic in nature. They are causing high damages in case of agriculture, horticulture and etc. Approximately 168 genera and 1000 rust species are found worldwide. They are able to produce up to five different spore producing structures like spermogonia, aecia, uredinia, telia and basidia throughout their lifecycle. Puccinia coronata, Puccinia striiformis are examples of Rusts fungi species.
Smuts
Smuts are typically pathogenic to cereals, crops and members of the grass family. They undergo reproduction and form dikaryotic hyphae ( by fusing to haploid cells). They produce a large number of dark, thick-walled, dust like teleospores. Tilletia laevis, Tilletia caries are examples of Smut species.
Mildews
Mildews are a group of fungi species slightly distinct from typical molds. They superficially grow on plant’s bodies or on organic matter such as wood, paper, leather, etc. They are appearing whitish in color and may cause damage to its host. Erysiphe cichoracearum, Erysiphe alphitoides are examples of some common mildew species.
Truffles
Truffles are a group of fungi species bearing a highly nutritious fruiting body. Most of the truffles live in a mutualistic relationship with a plant host. The mycelium forms mycorrhizal connection with the roots of that plant host and exchange nutrients. Truffles are used as a nutritional food supplement very largly. Tuber melanosporum, Tuber brumale are some most common truffle species.
Puffballs
Puffballs are another type of eukaryotic fungi examples bearing a brown dust like spores. Some species of Puffballs are highly poisonous and deadly. Puffballs lack the open cap with spore bearing gills that’s why the spores develop internally. After maturation the spores emitted. Most of the species do not have a typical stalk. Some examples of Puffball fungi species are Battarrea phalloides, Bovista dermoxantha, etc.
There are some microorganisms often called fungi but they are do not belongs to kingdom fungi. For example slime molds are unicellular eukaryotic organsims generally free living but in presence of obstacles they can achieve multicellular characteristics. They are often called as fungi but do not belongs to the kingdom fungi.
The Eukaryotic fungi are subdivided based on their mode of nutrition and on the basis of their spore formation methods.
Firstly based on their mode of nutrition, there are majorly three types of fungi species present, including parasites, saprophytes and symbionts.
Parasites: These are heterotrophic fungi, living on another organism’s body (host), absorbing nutrients from them for survival. They are majorly pathogenic to their host. For example Puccinia sp.
Saprophytes: These fungi species grow on dead and decaying organisms or on organic matters, and absorb nourishment from them. In nutrient cycling process the role of saprophyts is immense. For example Penicillium sp.
Symbionts : These fungi species share a mutualistic Symbiotic relationship with others. For example Tuber melanosporum, Tuber brumale are some most common symbiont fungi species among them.
Some symbiont fungi species associate with a plant host and make mycorrhiza (symbiosis relationship) where both of them benefited. The plant gives the fungi carbohydrates by photosynthesis and the fungi supplies plant water and minerals (phosphorus) to the plant.
Some fungi are associated with algae and develop symbiotic relationships between them, called Lichens. The algae synthesis carbohydrates for the fungi and the fungi gives shelter to that algae.
Based on the spore formation format there are following types of fungi species present-
Zygomycota: Zygomycota fungi species are the true kind of fungi forming hyphae and myclelium. They are able to produce more resistant spherical zygospores by reproduction. They also produce spongiospores. In case of zygospores two different kind of cells or hyphal strands are fused to make the it. They are majorly found in soil, on organic matters or on dead and decaying organisms. For example- Rhizopus stolonifer.
Ascomycota: They are commonly known as sac fungi. They bear an identifying reproductive structure called ascus (ascus means sac). Which forms non-motile spores, called ascospores. These fungi also able to form conidiospores. Mostly saprophytes. Examples- Baker’s Yeast or Saccharomyces cerevisiae.
Basidiomycota: Basidiomycota includes members of mushrooms, puffballs, yeasts,stinkhorns, etc. They are filamentous fungi producing basidiospores and conidia. Examples – Agaricus bisporus.
Deuteromycota: Commonly known as imperfect fungi as they do not follow any kind of reproduction rule. Their some reproduction phases remain unknown and they produce conidia. Examples- Trichoderma sp.
Chytridiomycota: Microscopic species, found in freshwater or wet soil. They mostly reproduce by forming motile zoospores having flagellum like whiplash structure posteriorly. Majorly parasitic and saprophytic in nature. Examples – Batrachochytrium dendrobatidis.
There is also a class called glomeromycetes under glomeromycota. Around 230 described species under this group. They are mostly arbuscular mycorrhizas with some plant species. They are mostly reproduce by forming glomeruspores through the hyphal tips. But the phylum glomeromycota is now invalid, only existing as class glomeromycetes.
Fungi are Eukaryotic organisms. They possess a membrane bound eukaryotic kind of well organized cell structure also having a member bound proper nucleus in it. They are predominantly multicellular and some are unicellular (yeast). Some eukaryotic fungi examples are mushrooms, molds, yeasts, truffles, etc.
They reproduce by forming different kinds of spores, such as ascospores, zygospores, basidiospores, zoospores, conidiospore, spongiospores, etc.
Multicellular fungi can develop hyphae and mycelium networks.
Alterations of generations can be seen in life cycle that means a fungi species have both haploid and diploid stages in their lifecycle alternatively.
They are non vascular organisms, that means they lack xylem and phloemtissues.
Fungi do not have any kind of embryonic stages in their lifecycle.
They are mostly non motile, remaining attached to some substance or it’s host.
They can store food as starch.
They are able to synthesize chitin in their body.
The fungi cells undergo mitosis and meiosis divisions. During division process the nuclear membrane does not dissolve.
To know more about DNA structure read our article on DNA Structure
As a whole, we briefly describe all the possible aspects of eukaryotic fungi examples. We discuss about the types of fungi species based on their mode of nutrition and based on their spore formation methods. Here we also mention all the eukaryotic characteristics of fungi. We know about some common associations between fungi species and some other organisms such as lichens, mycorrhizas, etc.
In this article, we will have a closer approach towards the nucleophilic substitution reaction mechanism, i.e., SN1 with appropriate SN1 examples.
What does the one stands for in the SN1 mechanism? Means that it follows first-order, or we can say the reaction rate depends only on the concentration of substrate. We will analyze the factors governing the reaction mechanism with various SN1 examples like carbocation stability, carbon skeleton, the leaving group, solvent, etc.
This reaction occurs in 2 steps:
Step 1: Formation of the carbocation.
Step 2: Reaction of carbocation with the nucleophile
Carbon skeleton structure: compounds forming stable carbocations react by the SN1 mechanism. Also, the substrate, which contains good leaving groups and adjacent substituents like a phenyl group that stabilizes a positive charge mesomerically, are prone to undergo SN1 reaction.
More substituted carbocation, i.e., tertiary carbon, readily forms carbocation, which is very stable. The stability of carbocation formed as an intermediate in the reaction plays a crucial role in determining the efficiency of the SN1 reaction.
Stability order of carbocation:
Tertiary > secondary > primary
Note: Planarity is so essential to the structure of a carbocation that if a tertiary cation cannot become planar, it is not formed.
Allylic electrophiles react well by the SN1 mechanism as the allyl cation is relatively stable , important sn1 example.
Treatment of cyclohexanol with HBr gives corresponding allylic bromide
Image Credit: Organic Chemistry by Jonathan Clayden, Nick Greeves, and Stuart Warren.
Image Credit: Organic Chemistry by Jonathan Clayden, Nick Greeves, and Stuart Warren.
An exceptional stable cation is formed when the three benzene rings stabilize the same positive charge. The resultant is the triphenylmethyl cation or trityl cation. Trityl chloride is used to form an ether with a primary alcohol group by the SN1 reaction.
Pyridine is used as a solvent for the reaction. Pyridine is not strong enough to remove the proton from the primary alcohol, and there would be no point in using a base strong enough to make RCH2O- as the nucleophile makes no difference to an SN1 reaction. Instead, the TrCl ionizes first to trityl cation, which now captures the primary alcohol, and finally, pyridine can remove the proton from the oxonium ion.
Pyridine does not catalyze the reaction; it stops it from becoming too acidic by removing the HCl formed. Pyridine is also a suitable polar organic solvent for ionic reactions.
Note: The reaction rate depends only on the concentration of substrate alone.
Nucleophile: Since the nucleophile comes into the picture after the rate-determining step, the strength or reactivity of a nucleophile plays no significant role in the SN1 mechanism.
Converting ROH into an Ester, i.e., sulfonic Ester group is relatively a good leaving group.
Effect o solvent: It is usually carried out in polar protic solvents because polar solvents stabilize the intermediate carbocation, increasing the rate of reaction. Reduces the effect of the nucleophile, solvates the carbocation and anion, thus imparts stability and hence favors SN1 mechanism.
In Sn1 mechanism polarity of the solvent is proportional to its respective dielectric constant. Ionization occurs faster in solvents with high polarities, such as water or alcohol.
Example: Consider the rate of solvolysis of 2-Bromo 2-methyl propane is said to be 3 × 104 times faster in 50% aqueous ethanol as compared to in 100% ethanol. This is the charge that is developed in the intermediate ion. As the polarity of the solvent increases, the stability of carbonium ion increases, and therefore rate of SN1 reaction increases. Essential sn1 example.
We know that carbocation carbon atoms consist of sp2 hybridization, so it should be planar and hence achiral. In the reaction of a chiral substrate, the attack can be at either side of the plane, yielding equal amounts of enantiomeric products formation, giving a racemization mixture.
At the time of many SN1 reactions, sometimes there is 6 to 21% inversion, and a sometimes small amount of configuration is retained. These results can be explained by citing the formation of ion pairs.
Image credit: Organic Chemistry mechanism by Ahluwalia
In contact or intimate ion pair, i.e., R+ does not act as a free cation of dissociated species. It is observed that the bond formation between R+ and X- the symmetry is adequately maintained, i.e., the originality of stereochemical configuration is retained by individual ions.
Hence in the SN1 mechanism, X- solvates a cation from the side where it is leaving, and the molecules of solvent around the intimate ion pair solvate only from the opposite side. This gives rise to the situation when carbocation is unsymmetrically solvated. On the attack of nucleophiles, the solvent molecules produce inverted products.
When a nucleophile attacks carbocations of solvent separated ion pair, the carbocations stereochemistry is not maintained tightly. There are chances that the leaving group can block the approach of a nucleophile to that particular side of the carbocation. Therefore formed products will have configuration inverted, giving a mixture of racemization.
Energy profile diagram of SN1 reaction: sn1 example t-butyl bromide and water
Image credit: Jonathan Clayden, Nick Greeves, and Stuart Warren
The carbocation is shown as an intermediate- a species with a finite (short) lifetime. And because we know that the first step, the carbocation formation, is slow, that must be the step with the higher energy transition state.
The energy of that transition state, which determines the overall rate of the reaction, is closely linked to the stability of the carbocation intermediate, and it is for this reason that the most important factor in determining the efficiency of the SN1 mechanism is the stability or otherwise of any carbocation that might be formed as an intermediate.
FAQs
1.How is the C-X bond polarized in the sn1 mechanism ?
It happens due to the electronegativity of halogens .
2. Why are sn1 reactions ?
It is said unimolecular because the rate of reaction depends only on concentration.
3.Why is it that the SN1 mechanism prefers polar protic solvents?
It prefers polar protic solvents because it stabilizes carbocation intermediate and reduces the activity of nucleophiles, and favors SN1 reaction.
4.What role does concentration play in the SN1 mechanism?
It depends only on substrate concentration and hasno effect onthe concentration of nucleophiles.
High friction refers to the resistance encountered when two surfaces come into contact with each other. It is a force that opposes the motion of an object and can be observed in various everyday situations. One common example of high friction is when you try to push a heavy object, such as a car, and it is difficult to get it moving. Another example is when you walk on a rough surface, like a gravel path, and your shoes grip the ground firmly. High friction is also experienced when you try to write with a pen on a rough paper surface. These examples demonstrate how friction can make it harder to move objects or change their state of motion.
Key Takeaways
Example
Description
Pushing a heavy object
It requires more force to overcome the resistance and get the object moving.
Walking on a rough surface
The friction between your shoes and the ground provides stability and prevents slipping.
Writing on rough paper
The friction between the pen and the paper allows the ink to transfer onto the surface.
High Friction Examples in Everyday Life
Friction is a force that occurs when two surfaces come into contact and resist each other’s motion. It plays a significant role in our daily lives, providing us with stability and control in various activities. Let’s explore some examples of high friction in everyday life.
Driving a Vehicle on a Surface
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When you drive a vehicle on a surface, such as a road or a parking lot, friction comes into play. The tires of the car grip the road surface, creating a high frictional force that allows the vehicle to move forward. Without friction, the tires would simply slide on the road, making it impossible to control the car.
Applying Brakes to Stop a Moving Vehicle
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When you apply the brakes to stop a moving vehicle, friction is essential in bringing the vehicle to a halt. The brake pads press against the rotating wheels, creating a high frictional force that converts the kinetic energy of the moving vehicle into heat. This frictional resistance slows down the vehicle and eventually brings it to a stop.
Skating
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Skating, whether it’s ice skating or roller skating, relies on friction to control movement. The blades or wheels of the skates grip the surface, creating a high frictional force that allows skaters to maneuver and change direction. Without friction, skaters would simply slide uncontrollably.
Walking on the Road
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When you walk on the road, friction between the soles of your shoes and the ground helps you maintain balance and prevent slipping. The high frictional force between your shoes and the road surface allows you to push off and move forward with each step. Without friction, walking would be challenging and unstable.
Writing on a Notebook/Blackboard
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When you write on a notebook or a blackboard, friction between the pen or chalk and the surface is crucial. The high frictional force between the writing instrument and the paper or board allows you to create legible marks. Without friction, the pen or chalk would simply slide across the surface without leaving any trace.
Flying of Airplanes
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Even though airplanes fly in the air, friction still plays a role in their operation. The wings of an airplane generate lift by creating a pressure difference between the upper and lower surfaces. This pressure difference is achieved by the shape of the wings and the high frictional force between the air and the wing surfaces.
Drilling a Nail into the Wall
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When you drill a nail into the wall, friction is essential in keeping the nail in place. The high frictional force between the nail and the wall surface prevents it from easily sliding out. This allows you to hang objects securely without worrying about them falling down.
Sliding on a Garden Slide
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When you slide down a garden slide, friction between your body and the slide surface provides the necessary resistance. The high frictional force slows down your descent, ensuring a controlled and enjoyable sliding experience. Without friction, sliding down the slide would be too fast and potentially dangerous.
These examples highlight the importance of friction in our everyday lives. Whether it’s driving, walking, or engaging in various activities, friction allows us to have control, stability, and safety. So the next time you encounter friction, remember its role in making things possible!
Lighting a Matchstick
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Lighting a matchstick is a simple yet fascinating process. By striking the match against a rough surface, we create the necessary friction to ignite the match head. This friction generates heat, which then causes the chemicals on the match head to react, resulting in a flame. It’s a perfect example of how friction plays a crucial role in our daily lives.
Friction, in physics, is the force that resists the relative motion between two surfaces in contact. There are different types of friction, including static friction, kinetic friction, and sliding friction. When it comes to lighting a matchstick, we primarily rely on static friction to initiate the flame.
Static friction is the force that prevents an object from moving when a force is applied to it. In the case of a matchstick, the frictional force between the match head and the striking surface keeps the matchstick stationary until we apply enough force to overcome this static friction. Once the matchstick starts moving, the static friction transitions into kinetic friction, which allows the matchstick to slide along the striking surface.
Now, let’s shift our focus to another interesting topic related to friction: dusting a foot mat or carpet by beating it with a stick.
Dusting a Foot Mat/Carpet by Beating it with a Stick
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Dusting a foot mat or carpet by beating it with a stick is a common practice to remove dust, dirt, and debris that accumulate on the surface. This method utilizes the principle of friction to dislodge and remove particles from the mat or carpet fibers.
When we beat the foot mat or carpet with a stick, the impact creates a high friction force between the stick and the mat/carpet surface. This frictional force helps to loosen the dust particles that have settled within the fibers. The repeated strikes cause the particles to dislodge and become airborne, allowing them to be easily swept away or vacuumed.
The high friction surfaces of the stick and the mat/carpet work together to create an aggregate value of resistance, resulting in the abrasion of the dust particles. The stick’s surface, which is generally rough or textured, helps to polish the mat/carpet surface, removing any stubborn dirt or stains.
In the case of a car, friction also plays a crucial role in the braking system. When we apply the brakes, the brake pads come into contact with the brake discs or drums, creating friction. This frictional force helps to stop the car by converting the kinetic energy of the moving car into heat energy. The higher the friction between the brake pads and the braking surface, the quicker the car comes to a halt.
Similarly, when we touch a high friction surface like a carpet, we can feel the resistance or frictional force as we move our hand across it. This resistance is due to the microtexture of the carpet fibers, which create a high friction coefficient. This high friction coefficient allows the carpet to provide traction and prevent slipping, making it a suitable flooring option for areas where safety is a concern, such as staircases.
Friction is not only essential in our daily lives but also finds applications in various industries. For example, in sports like rock climbing, the friction between the climber’s hands and the rock surface allows them to grip and ascend. In engineering, high friction materials are used in applications where increased friction is desired, such as conveyor belts or brake pads.
Understanding High Friction
Friction is a fundamental concept in physics that plays a crucial role in our daily lives. It refers to the resistance encountered when two surfaces come into contact and try to slide or move against each other. Understanding high friction is important as it helps us comprehend the factors that contribute to this resistance and its various applications.
What Produces Friction?
Friction is caused by the interaction between the surfaces of two objects. When these surfaces come into contact, irregularities at the microscopic level, such as bumps and ridges, create resistance. This resistance is known as frictional force. There are different types of friction, including static friction, kinetic friction, and sliding friction.
Static friction occurs when two surfaces are at rest and trying to move against each other. It prevents objects from sliding until a certain force is applied to overcome the static frictional resistance. Once the force exceeds the static friction, the objects start moving, and kinetic friction comes into play. Kinetic friction is the resistance encountered when two surfaces are in motion relative to each other. Sliding friction, on the other hand, refers to the resistance experienced when an object slides across a surface.
Which Surfaces Have the Most Friction?
The amount of friction between two surfaces depends on several factors. One of the key factors is the nature of the surfaces themselves. Surfaces with high friction coefficients tend to have a rough texture or microtexture, which increases the frictional force. For example, a carpet has a higher friction coefficient compared to a smooth tile floor. The carpet’s fibers create more resistance, making it harder to slide or move on.
Another factor that affects friction is the force applied between the surfaces. The greater the force, the higher the frictional resistance. For instance, when you apply the brakes in a car, the brake pads come into contact with the surface of the brake rotor. The force applied by the brake caliper increases the friction, allowing the car to stop.
High Friction Combinations of Surfaces
Certain combinations of surfaces result in high friction. These combinations are often utilized in various applications where increased friction is desirable. Here are a few examples:
Rock Climbing: Rock climbers rely on high friction surfaces to grip and ascend steep rock faces. The rubber soles of climbing shoes provide excellent traction on rough rock surfaces, allowing climbers to maintain their grip.
Automotive Brakes: The friction between the brake pads and the brake rotors is crucial for stopping a car. High friction materials, such as ceramic or composite brake pads, are used to ensure efficient braking performance.
Tire Friction: The friction between tires and the road is essential for maintaining control and preventing skidding. Tire manufacturers design tread patterns and use high friction rubber compounds to maximize grip on different road surfaces.
Safety Measures: High friction surfaces are often employed in safety measures to prevent accidents. For example, textured or abrasive materials are used on stair treads or walkways to provide better traction and reduce the risk of slipping.
The Impact of High Friction
Friction is a fundamental concept in physics that describes the resistance encountered when two surfaces come into contact and try to slide past each other. It plays a crucial role in our daily lives, affecting various aspects of our environment, technology, and even sports. While friction is essential for many processes, such as walking or driving, high levels of friction can have both beneficial and detrimental effects.
What Can Happen if Friction is Too High or Too Low?
Friction can have different effects depending on whether it is too high or too low. When friction is too high, it can cause excessive resistance, making it difficult for objects to move or slide. This can lead to wear and tear, as well as increased energy consumption. On the other hand, when friction is too low, objects may slide too easily, resulting in a lack of control and stability.
There are several examples where high friction can be harmful. One such example is the excessive friction between moving parts in machinery or engines. This can lead to increased wear and tear, reduced efficiency, and even mechanical failures. Another example is the high friction between automotive brakes and the surface of the road. While this friction is necessary for stopping the vehicle, excessive friction can cause the brakes to overheat, leading to decreased braking performance and potential accidents.
Instances Where Friction is Not Useful
While friction is generally beneficial and necessary, there are instances where it is not useful or even undesirable. For example, in certain industrial processes, such as conveyor belts or assembly lines, excessive friction can cause jams or slowdowns, disrupting the workflow. In sports, high friction can hinder performance, such as in rock climbing, where too much friction can make it difficult to ascend. Additionally, in safety measures, high friction surfaces can cause injuries, such as carpet burns or skin abrasions.
In engineering, friction is carefully considered and controlled to optimize performance. High friction materials, such as high friction rubber, are used in applications where increased friction is desired, such as automotive tires or industrial belts. Friction also plays a crucial role in motion control systems, where it is used to create precise movements and prevent unwanted sliding.
High Friction in Mechanical Engineering
Friction is a fundamental concept in physics that plays a crucial role in various aspects of our daily lives, including mechanical engineering. It refers to the resistance encountered when two surfaces come into contact and attempt to slide or move relative to each other. In mechanical engineering, high friction surfaces and mechanisms are of particular interest due to their unique characteristics and applications.
High Friction Mechanism in Tribology
Tribology, the study of friction, lubrication, and wear, explores the mechanisms behind high friction surfaces. When two surfaces are in contact, the frictional force between them can be influenced by several factors. One such factor is the nature of the surfaces themselves. The roughness, texture, and material properties of the surfaces can significantly impact the frictional resistance experienced.
In high friction surfaces, the microtexture and aggregate value of the surface play a crucial role. Surfaces with a higher microtexture tend to have increased friction due to the increased contact area between the surfaces. Similarly, surfaces with a higher aggregate value, which refers to the overall roughness of the surface, also exhibit higher frictional resistance.
Examples of high friction surfaces can be found in various engineering applications. For instance, automotive brakes rely on high friction materials to effectively stop a moving vehicle. The frictional force between the brake pads and the rotor creates the necessary resistance to bring the car to a halt. Similarly, in sports such as rock climbing, the friction between the climber’s hands or feet and the rock surface allows for secure grip and movement.
High Erosion Model in High Friction Surfaces
In addition to the high friction mechanism, high friction surfaces can also be subject to erosion and wear. The constant interaction and sliding between two surfaces can lead to abrasion and the gradual removal of material from the surfaces. This erosion can affect the performance and longevity of the surfaces involved.
To mitigate erosion in high friction surfaces, engineers employ various techniques and materials. High friction rubber, for example, is often used in applications where both grip and durability are essential, such as in industrial settings or safety measures. The high friction coefficient of these materials ensures a secure grip while minimizing wear and tear.
In industry, high friction surfaces are utilized in applications where motion control and stability are crucial. Conveyor belts, for instance, rely on high friction surfaces to prevent items from sliding during transportation. The high friction between the belt and the items being conveyed ensures their safe and efficient movement.
Frequently Asked Questions (FAQs)
5 Examples of High Friction
Friction is a force that resists the motion of objects in contact with each other. It plays a crucial role in our daily lives and various industries. Here are five examples of high friction:
Automotive Brakes: When you apply the brakes in a car, the friction between the brake pads and the rotors creates a high frictional force, allowing the car to stop effectively.
Rock Climbing: Rock climbers heavily rely on friction to ascend steep surfaces. The friction between their climbing shoes and the rock surface provides the necessary grip and stability.
Tire Friction: The friction between the tires of a vehicle and the road surface is essential for traction and control. It allows the tires to grip the road, preventing skidding and ensuring safe driving.
High Friction Surfaces: Certain surfaces, such as sandpaper or rubber mats, are intentionally designed to have high friction. These surfaces provide increased grip and prevent slipping, making them useful in various applications.
Sports Equipment: Friction plays a significant role in sports like tennis, where the friction between the tennis ball and the racket strings determines the amount of control and spin a player can achieve.
3 Examples Where Friction is Useful
Friction is not always a hindrance; it can be beneficial in several situations. Here are three examples where friction is useful:
Walking: Friction between our shoes and the ground allows us to walk without slipping. It provides the necessary grip and stability, enabling us to move forward.
Writing: When we write with a pen or pencil, the friction between the writing instrument‘s tip and the paper allows the ink or graphite to transfer onto the surface, creating legible writing.
Safety Measures: Friction is utilized in safety measures like seatbelts and airbags. The frictional resistance between the seatbelt and the passenger’s body helps restrain them during sudden deceleration or impact, reducing the risk of injury.
10 Examples Where Friction is Not Useful
While friction has many practical applications, there are instances where it can be undesirable. Here are ten examples where friction is not useful:
Heat Generation: Friction between moving parts in machinery can generate heat, leading to energy loss and potential damage to the components. This is why lubricants are used to reduce friction and minimize heat generation.
Wear and Tear: Friction between two surfaces in contact can cause abrasion and wear over time. This is evident in the wearing down of shoe soles or the degradation of mechanical parts.
Sliding Doors: Excessive friction in sliding doors can make them difficult to open or close smoothly. To overcome this, lubricants or rollers are often used to reduce friction and ensure smooth operation.
Efficiency Loss: Friction in mechanical systems can result in energy loss, reducing overall efficiency. This is why engineers strive to minimize friction in engines, gears, and other moving parts.
Air Resistance: When objects move through the air, frictional resistance, also known as air resistance, can slow them down. This is particularly noticeable in activities like cycling or running against strong winds.
Fluid Flow: Friction between a fluid and the walls of a pipe or conduit can impede the flow, reducing efficiency. Smooth pipes or the use of lubricants can help minimize friction and improve fluid flow.
Noise Generation: Friction between certain materials can produce unwanted noise. For example, squeaky hinges or screeching brakes are caused by friction between metal surfaces.
Sticking or Jamming: Excessive friction can cause objects to stick or jam together, making it difficult to separate them. This can be observed in rusty bolts or doors that are hard to open due to friction.
High-Speed Applications: In high-speed applications like racing cars or aircraft, excessive friction can generate heat and wear, compromising performance and safety. Specialized materials and lubrication are used to minimize friction in such cases.
Effort Required: Friction can make it more challenging to move objects, requiring more force or effort. This can be seen when pushing a heavy piece of furniture or dragging a suitcase on a rough surface.
Remember, while friction can be both useful and problematic, understanding its principles and managing it appropriately allows us to harness its benefits while minimizing its drawbacks.
What are some high friction examples and how do they relate to the principles of a frictionless table?
High friction examples encompass various scenarios where friction plays a significant role. When discussing the principles of a frictionless table, it becomes crucial to examine the concept of friction comprehensively. A frictionless table, as explored in the article “Principles of a frictionless table,” involves reducing or eliminating friction between the surfaces in contact. By understanding high friction examples, we can better appreciate the significance and benefits of a frictionless table. These principles contribute to the design and engineering of surfaces that minimize or eliminate friction, enhancing efficiency and reducing wear and tear.
Frequently Asked Questions
1. What is the definition of friction in mechanical engineering?
Friction in mechanical engineering is the resistance to motion of one object moving relative to another. It is caused by the interactions between the surfaces of the two objects and is divided into static friction (friction between two or more solid objects that are not moving relative to each other) and kinetic friction (friction between two or more solid objects that are moving relative to each other).
2. Can you provide 5 examples of high friction in everyday life?
Sure, here are five examples:
1. Rubbing hands together to generate heat.
2. A car’s brakes slowing the vehicle down.
3. Walking without slipping, as the friction between shoes and the ground prevents sliding.
4. Writing with a pencil, where friction between the pencil lead and paper allows the writing to appear.
5. Rock climbing, where friction between the climber’s hands/feet and the rock surface allows for grip.
3. What is the significance of friction in sports?
Friction plays a crucial role in sports. For instance, in games like football, basketball, or tennis, the friction between the ball and the playing surface affects the ball‘s speed and direction. In athletics, the friction between the athletes’ shoes and the track surface provides the grip needed for running. In sports like ice skating, low friction between the skates and ice surface is necessary for smooth movement.
4. How does friction relate to safety measures?
Friction is integral to many safety measures. For example, the high friction between tires and the road surface allows vehicles to stop safely when brakes are applied. Similarly, the friction between our shoes and the floor prevents us from slipping. In industrial safety, gloves with high friction surfaces are used to securely handle slippery objects.
5. What is a high friction surface and can you give an example?
A high friction surface is one that creates a large amount of resistance to the motion of another object sliding or moving over it. Examples include sandpaper, rubber, and concrete. These surfaces are often used in applications where it’s important to reduce slippage, such as in the soles of shoes or tires.
6. What is the role of friction in automotive brakes?
In automotive brakes, when the brake pedal is pressed, it creates friction between the brake pads and the brake disc. This friction slows down the rotation of the wheels, thereby slowing down or stopping the vehicle. The effectiveness of the braking system heavily depends on the high friction produced in this process.
7. How does the combination of surface materials affect friction?
The combination of surface materials can greatly affect the level of friction produced. For example, ice on metal (like in ice skating) produces low friction, allowing for smooth and fast movement. Conversely, rubber on concrete (like car tires on a road) produces high friction, providing grip and preventing slippage.
8. What is the frictional force and how is it related to motion?
Frictional force is the force exerted by a surface when an object moves across it or makes an effort to move across it. It opposes the motion of the object. Without frictional force, an object in motion would continue moving indefinitely. It is friction that slows down and eventually stops the motion of objects.
9. Can you provide examples where friction is not useful?
While friction is essential in many scenarios, there are situations where it is not useful or even harmful. For example, in machinery, friction between moving parts can cause wear and tear, leading to damage over time. Similarly, in vehicles, friction can reduce efficiency by causing resistance to motion, leading to increased fuel consumption.
10. What are high friction applications in the industry?
In the industry, high friction applications are numerous. They include braking systems in vehicles, conveyor belts, clutches, and any system where it’s necessary to control or stop the movement of machinery. High friction materials, such as certain types of rubber and metal alloys, are often used in these applications.
Heterotrophic bacteria are one of the most important consumers of the ecosystem. Here we try to discuss all possible aspects of heterotrophic bacteria examples.
Heterotophic bacteria examples
According to their food resources, there are three different types of heterotrophic bacteria present in the ecosystem
Parasitic: The parasitic bacteria derive energy from other living organisms. They consume energy from plants and animals. Some parasitic bacteria are pathogenic to the host. For example, Xanthomonas campestris causes blight on beans. Vibrio cholerae causes cholera in humans.
Heterotrophs are non-producer organisms of the ecosystem.
Organisms, who consume the producer and other consumer organisms to fulfill their need for nutrients and energy are known as heterotrophs. They can be the primary, secondary or tertiary consumers of the food chain.
For example, all animals are heterotrophic because they consume nutrients from others by eating them. Bacteria, who are heterotrophic in nature are known as heterotrophic bacteria.
Can some bacteria be heterotrophic?
Heterotrophic bacteria are one of the largest group of animals under the ecosystem.
Some heterotrophic bacteria derive nutrition from living organisms and show parasitic interaction with that organism. Some heterotrophic bacteria live on dead organisms or organic matter and absorb nutrients from it.
Where can you find heterotrophic bacteria?
Heterotrophic bacteria are widely spread all over the world. Bacteria are one of the most abundant species world wide.
Approximately 2×1030 bacteria are present on the Earth. From air to soil, food, water, glaciers, hot springs, chemical wastes, it can be found everywhere. Some heterotrophic bacteria, as a parasite, can be found in various plants, animals and also in human bodies.
What are the structural features of heterotrophic bacteria?
The heterotrophic bacteria usually possess different sizes and shapes. Some are typically few micrometres in length. They comprise a primitive, prokaryotic kind of cellular structure.
Simple cellular structure with capsule, cell wall, cytoplasm, chromosomes.
Prokaryotic 70S ribosomes are present within cytoplasm. The two subunits are 30S and 50S.
The cell wall composition is a thick or thin layer of peptidoglycan also called murein, that differs in gram-positive bacteria and gram-negative bacteria.
Heterotrophic bacteria play many significant roles to maintain the balance of our ecosystem.
Decomposition: One of the major roles of heterotrophic bacteria is the decomposition process. Saprophytic bacteria grow on dead and decaying organisms and absorbs nutrients from them. They break the organisms into simple compounds and decompose them.
Nutrients cycling: The heterotrophic bacteria play a significant role in the nutrient cycling process. Through the biodegradation process the microbes restore different organic matters into the soil. They help to regulate organic matter cycles like carbon cycle, nitrogen cycle, and phosphorus cycle in the ecosystem.
Human survival: There are some bacteria, live in human bodies that help us in many ways. Bacteria like Bifidobacteria, E.coli, live inside the human body (digestive tract) and help in digestion. They break the food particles into simple forms.
Nitrogen fixation: Some symbiotic bacteria like Rhizobium live in the root nodules of legumes. They obtain the nitrogen from free air and restore the nitrogen as nitrates or ammonia or nitrites into the soil.
Food technology: Some bacteria help in the fermentation process. Bacteria like Lactobacillus and Lactococcus (lactic acid bacteria) prepare yogurt, cheese from milk. Other bacteria can prepare soy sauce, vinegar, pickles, etc. This way these bacteria are very important in food technology.
Pathogenicity: There are some parasitic bacteria also which can cause different types of disease in their host. For example, cholera is caused by Vibrio cholerae, diphtheria is caused by Corynebacterium diphtheriae, bubonic plague is caused by Yersinia pestis, pneumonia is caused by Streptococcus pneumonia. The bacteria attack the human body and enter. The immune system recognises the foreign antigen and starts to react.
Disease caused by heterotrophic bacteria from pixabay
Is Bacillus heterotrophic bacteria?
Yes, Bacillus is heterotrophic bacteria that means it cannot make its own food. It depends on others for their nutrition.
For example, Bacillus cereus is a heterotrophic bacterium which decomposes organic matter and absorbs nourishment from them.
Is legionella heterotrophic bacteria?
Legionella is a heterotrophic bacteriam which has pathogenicity. It causes a type of pneumonia (lung infection) called Legionnaires’ disease and illness called Pontiac fever. It highly infects its host and causes diseases.
For example Legionella pneumophila is a primary human pathogenic bacteria that cause legionellosis.
Are heterotrophic bacteria decomposers?
Among three different types of heterotrophic bacteria, some bacteria act as decomposers.
The saprophytic bacteria grows on dead organisms or organic matter and breaks the organic compounds and melts (decomposition) them into the soil. These kind of heterotrophic bacterias are the example of decomposers.
For example Bacillus subtilis and Pseudomonas fluorescens are some common saprophytes that help in the decomposition process.
Are heterotrophic bacteria unicellular?
Yes, heterotrophic bacteria are unicellular prokaryotic organisms. That means it consists of a single cell, which carries out all of the required functions of that organism.
Are heterotrophic bacteria prokaryotic or eukaryotic?
Heterotrophic bacteria typically have a single prokaryotic type of cell that means they are typically prokaryotes.
Do heterotrophic bacteria need oxygen?
There are two kinds of bacteria present. Some bacteria need oxygen to survive and some bacteria don’t need oxygen to survive.
According to their need for oxygen bacteria can be classified in two different categories like aerobic and anaerobic.
The aerobic bacteria need oxygen to grow and survive in the environment. Bacteria like Nocardia sp. and Pseudomonas aeruginosa need oxygen for their metabolic functions.
The anaerobic bacteria can survive without oxygen. In some obligate anaerobes the presence of oxygen, can disrupt their metabolism and even kill them. For example, Chytridiomycota is an obligate anaerobe that lives in the rumen of cattle and uses anaerobic respiration process.
Why do heterotrophs need nitrogen?
Heterotrophs need nitrogen because nitrogen is a part of their cellular structure. Amino acids, genetic materials, ATP everything is made up of nitrogen molecules. So nitrogen is very essential for them.
How do heterotrophs obtain phosphorus?
Most heterotrophs get phosphorus from their food resources (producers or other consumers or dead and decaying organisms). They obtain the phosphorus by absorbing it from another organism’s body.
How is nitrogen obtained by heterotrophs?
Heterotrophs obtain nitrogen from other organisms as nitrate compounds from whom they eat or depend on for nutrition. Some bacteria who are capable of nitrogen fixation process obtain nitrogen from free air and obtain that.
How do heterotrophs consume energy?
Heterotrophs are typically consumers. They cannot make their food to survive.
Heterotrophs consume energy from other organisms. They eat other producers or consumers and consume energy from them. Some parasitic heterotrophs obtain energy from their host. Some heterotrophs consume energy from dead or decaying organisms (saprophytes).
As a whole, we can say that heterotrophic bacteria are one of the pillars of our ecosystem.There are several kinds of bacteria present all around us. We give a clear idea about heterotrophic bacteria examples. Their role in maintaining the integrity of the ecosystem is immense.
In this article, we are going to discuss several muscular force examples that we often come across in our daily life.
The following is a list of muscular force examples that we are going to discuss here below:-
What is muscular force?
We perform various activities using muscular force; while playing, lifting any objects, walking, riding, cooking, pushing, pulling, workouts, etc.
Any activity utilizing the muscles to do the work is called the muscular force. It is applicable only when the object is in close contact with the body, hence it is a contact force.
Muscular Force Examples
In our day-to-day life, we make a lot of use of the muscular force almost for all activities. Let us discuss some of the muscular force examples.
Chewing: To mix the food particles with saliva and break the food into a bolus in the mouth we chew the food. To chew the food we make a rapid movement of the muscles to open and close the jaws. Hence chewing is associated with muscular force by the jaw muscles.
Man walking staircase: While walking the staircase, a man applies pressure on the front leg to lift his back leg and place it on the step ahead. This motion is possible due to the muscular movement of the legs. The force required to do so is a muscular force.
Squeezing wet clothes: To drain out the water from the wet clothes, the clothes are twisted by applying force from both the hands in the opposite direction holding both the ends of the cloth using the muscles on hand, hence is also a muscular force example.
Riding a bicycle: Riding a bicycle is a good exercise to improve blood circulation in the body. For a rider to keep the bicycle in momentum, the bicycler needs to continuously paddle the bicycle. The muscular force is applied to paddle the bicycle. The brakes are applied using the hand, to control the speed of the cycle. This also needs a muscular force. For riding a bicycle, the muscular force from both, the arms, as well as the legs are used.
Playing: While playing different games we often use a muscular force. For a footballer to kick a ball, various joints and muscles from the lower part of the body are used. The primary muscle situated on the lower leg utilized to kick the football is the tibia. The power required to kick the ball comes from the knee and hip when it is extended to kick the ball. The extension of the knee results in the contraction of the thigh muscles. These muscles are called quadriceps.
To hit the badminton cork, for throwing the ball in the air, playing with the ring, volleyball, basketball, etc. calf and soleus muscles present on the back of the lower leg give the energy to hit the cork. From upper body pectoral muscle on the chest, deltoids on the shoulder and even the abdominal muscles work in the movement while playing badminton.
Trapezium muscle on the back of the neck and upper backbone also helps during the motion, catching the ball, playing tennis, badminton, passing the ball, etc.
For playing kho-kho, running, or squatting, quadriceps and hamstring muscles are used. While running, the athlete pushes the body forward by applying pressure on the ground by his/her feet. The muscles and ligament that runs along the feet connect the calf muscle on the lower leg helps in doing so, and is very essential for running, standing, walking, and jumping, for locomotion.
Many athletes and players find it is very essential to maintain their muscle strength and build muscles so that it will provide them enough muscular force to perform better in sports.
Pushing: The force applied on the object to move the object away from self is called pushing. The muscular force is imposed on the object to displace the object from one place to another. The force is applied on the object using muscle on hand. Triceps, biceps, deltoids, and abdominal muscles play a major role while pushing heavier objects. Along with calm and thigh muscles on legs are used to apply the pressure on the ground that gives support to put a force on the object. Examples are, pushing a door, shopping trolley, boxes with load, etc., which are associated with the muscular force that is exerted on the object using hands.
A man pushing a box
Pulling: The force applied on the object to move the object closer towards the self is called pulling. The objects are pulled by the hand, using joints and muscles on hand; hence it is an example of muscular force. Some examples of pulling are opening the door or box, flying a kite, opening a drawer, pulling a trolley bag, etc.
A girl pulling a trolley; Image credit: clipground
Lifting: To lift any object in the hands, pectoral muscle, arms, and abdominal muscles are used. Since different muscles are utilized in doing so, it is a muscular force. Examples are: lifting a bucket full of water, lifting dumbbells, carrying a stack of books, etc.
Squeezing: To squeeze the juices from the lemon or orange, to squeeze water from the sponge, or to squeeze out the toothpaste from the tube, the hand palm is required to contract or expand the muscles on the hand as per the need. The muscles on hand contract while applying pressure and relax after removing the pressure. The hand muscles are used in doing this, hence is an example of muscular force.
Bulls ploughing the field: Ploughing is the most ancient and primitive activity practiced in the field before sowing the seeds to germinate. Even today in some parts of the country ploughing of the field is done from the bulls. The muscular force of the bull is used to drive the plough and helps to loosen the soil and weeding too. Hence ploughing is also a muscular force example.
Pushups on the ground: Pushup is a common exercise performed by raising and lowering the body using arms. The pectoral muscles on the chest support arms to raise and lower the body. A deltoid muscle on the shoulder helps the pectoralis muscles to push the body. Triceps in the upper hand helps in extending the arms outward and abdominal muscles where the center of gravity of the human body pertains provides a core strength to brace the body during pushups.
Drawing water from the well: To draw water from the well, we use a rope on the pulley and pull it toward ourselves. Doing this task without a pulley requires a lot of muscular power from deltoids. A lot of muscular strength by hands is utilized to draw out the water from the well. Using a pulley helps to reduce the force required and save energy. It reverses the direction of pulling; we pull the rope downward instead of upward by using a pulley, thus making it easier to apply the muscular force to pull the rope.
Playing musical instruments: Playing a musical instrument helps to communicate better between both the right and left brain and strengthens your memory power.
To play any string musical instrument maybe guitar, violin, viola, etc. we use all the muscles on hand, from palm, wrist, forearm to arms. Every muscle on hand exercises while playing the instrument thus helping to build the muscles too because muscles are in constant action while applying pressure on strings to playing a melody or chords.
The muscular force from hand and wrist, and obviously from mouth and face are used while playing instruments like saxophone, trumpet, flute, shehnai, tuba, clarinet, etc. To blow wind in an instrument, the diaphragm helps in inhalation. Hence, this is also an example of muscular force.
To press the keys on the piano, keyboard, organ, the muscle bulk on the fingers gives the strength to press the keys while playing a rhythm.
Controlling steering of a car: To hold a grip on steer on wheels of a car, we apply force by hand on the steer firmly. The force applied on the steer is equal to the torque applied upon the radius of the steering wheel. The muscles on the hand and palm are used to apply the force while steering, hence it is also a muscular force example.
There are various types of force existing in nature, like gravitational force, electrostatic force, magnetic force, frictional force, etc.
A force that results due to the movement of the muscles and is applied on the object using muscle strength by humans and animals is called a muscular force. Humans and animals can migrate, do the movements and perform various activities only because of the muscular force.
Is muscular force a contact force or a non-contact force?
The force applied on the object without physical contact is a non-contact force, whereas the force applied on the object being in close contact with that object is called a contact force.
The muscular force is applied on the object only by means of physical contact with the object to get the work done and it does not depend upon the external field, hence muscular force is a contact force.
From where do the muscles get the energy to produce a muscular force?
Enough energy is utilized to perform a day-to-day activity that utilizes muscular force.
The muscles get energy from the stored chemical energy that we received from food that we eat, which is converted into heat and energy. In its rest state muscles have energy stored with them in the form of potential energy and the same is converted into kinetic energy during the motion of a body.
In this article, we are going to have a closer approach towards the nucleophilic substitution reaction mechanism i.e.SN2 using the appropriate sn2 examples and why there is a need for us to analyse this mechanism.
We will study the mechanism in detail using the SN2 examples, the factors affecting the mechanism such as nucleophile strength, carbon skeleton, leaving group, solvent etc. The stereochemistry involved in the reaction, rate-determining factors and the healthy ways to carry out the reaction to achieve the desired result.
First of all, why there is a need for us to know which mechanism a reaction will follow? It is simply because it helps in predicting the type of conditions that are required for a substance to react in order to obtain good yield of products. So we shall have closer approach using SN2 examples.
Note:Rate of the reaction depends on the concentration of both nucleophile and substrate.
The name SN2 stands for nucleophilic substitution – second-order reaction. In this reaction mechanism, a nucleophile attacks a substrate and a leaving group leaves and this occurs simultaneously. The reaction occurs in one single step only.
SN2 example
In the above reaction of SN2 example OH acts as a nucleophile attacks and simultaneously chlorine which is a good leaving group leaves, OH comes and attaches at that point.
Nucleophile: It plays a very important role in the mechanism as it determines the rate of the reaction and the stronger the nucleophile faster will be the reaction. Negatively charged species are more nucleophilic as compared to neutral molecules. OH is preferred over other nucleophiles as it is an anion and hence very reactive.
Carbon skeleton: It always prefers primary carbon over tertiary carbon because if the carbon is more substituted(tertiary) than due to steric hindrance it becomes difficult for a nucleophile to attack the substrate.
Note: Methyl and primary alkyl group always react by SN2 mechanism and never by SN1 mechanism because it cannot form carbocation.
Leaving group : If the leaving group is good then the reaction will proceed faster resulting in an increase in the rate of reaction. Usually, the weak bases are good leaving groups which include ions of halides I-, Cl- and Br- also H2O. The important factors for leaving groups such as halide is the strength of the C-halide bond and the stability of the ion of halide.
Halides as leaving groups Image credit: Organic Chemistry Second edition by Jonathan Clayden, Nick Greeves and Stuart Warren.
Stereochemistry : When the leaving group is attached to a chiral carbon, inversion of configuration of substrate takes place. It happens because the nucleophile attacks just opposite to the leaving group .
Transition state tells us the type of structures that react reliably and stereochemistry of the reaction.
Effect of solvent : It is mostly carried out in polar aprotic solvent as the polar solvent aids in dissociation of the C-X bond where X is the leaving group and aprotic solvents solvate the leaving group thus accelerating the reaction.
Other factors influencing reaction mechanismusing sn2 examples :
When adjacent C=C or C=O π systems are present, they increase the rate of reaction mechanism. Consider the SN2 examples of Allyl bromide ,it reacts with alkoxides and forms ethers . It is observed that in the SN2 mechanism compounds of Allyl bromide react rapidly as the π system which is adjacent to the double bond stabilizes the state of transition by conjugation .
The p orbital present at the centre of the reaction makes two partial bonds having only two electrons (electron-deficient) so additional electron density can be gathered from adjacent π system which stabilizes the state of transition and hence the rate of reaction increases.
Among all the SN2 reactions when the leaving group is present adjacent to the Carbonyl group the reaction proceeds much faster.
SN2 Example :Benzyl bromide and alkoxides react to give Benzyl Ethers
Reaction of amine Image credit: Organic Chemistry Second edition by Jonathan Clayden, Nick Greeves and Stuart Warren.
In the above reaction of SN2 examples , amine reacts to form aminoketone which plays vital role in the synthesis of drugs .
Mostly alcohols are not good leaving group, so to resolve this problem :
• We can protonate the OH group with strong acid. This converts alcohol to it’s respective oxonium ion which can be lost as water.
• We know that sulfonate’s are good leaving group, so we can use the Tosyl group such as Tosyl chloride or Mesyl chloride replace the H with the Tosyl group thus resulting in alkyl sulfonate .
Amines are great nucleophiles but the reaction of ammonia and alkyl halides will not always form single products. This is because the product formed from the substitution is almost equally nucleophilic like the starting material and hence competes with alkyl halide in the reaction.
Reaction of amine with alkyl halide Image credit: Organic ChemistrySecond edition by Jonathan Clayden, Nick Greeves and Stuart Warren.
This alkylation continuous leading to the formation of secondary, tertiary and stops only on formation of non-nucleophilic tetra-alkylammonium ion. This extra groups of alkyl push the electron density onto N resulting the product to be more reactive than the previous one.
This problem can be overcome by replacing ammonia with the azide ion. It is a triatomic species which is nucleophilic at both it’s ends. It is a slender rod consisting of electrons which is capable to insert itself in all kinds of electrophilic site. It’s availability is in the form of water soluble sodium salt NaN3.
Azide reacts only once with alkyl halides as the product formed i.e alkyl halide is no longer in nucleophilic state.
Let’s have a closer approach towards the potential energy profile of the SN2 reaction.
When we go from left to right in the periodic table the nucleophilicity decreases followed by increase in electronegativity from left to right. Hence high electronegativity is unfavourable as the tightly held electrons are relatively less available for the donation to the substrate in the SN2 reaction. Therefore OH is said to be more nucleophilic than F- and NH3 is more nucleophilic than H2O.
Energy profile diagram Image credit: Organic Chemistry mechanism by Ahluwalia
Note: Harder nucleophiles increase the rate of reaction as compared to soft nucleophiles.
The potential energy profile of the SN2 mechanism above shows that only one transition state exists and there is no formation of intermediate between reactant and product as it’s a single step reaction. The energy of reactants is slightly higher than that of products as the reactions is an exothermic reaction.
The energy of transition state is quite higher as it involves a five- coordinated carbon atoms consisting of two partial bonds. The hill which is on the topmost part corresponds to the transition state of the Sn2 reaction. The free energy of activation corresponds to the difference in the free energy between the reactants and the transition state.
The free energy change for a reaction corresponds to the difference in free energy between the reactants and the products. A reaction will occur faster when it has low free energy of activation as compared to the one having higher free energy of activation.
Hard nucleophiles include- H-, CH3-
Moderate nucleophile – R-O- , R-NH-
Soft nucleophile – Cl-,
Frequently Asked Questions–
1. Why is Sn2 reaction mechanism not favorable or slower in polar protic solvents ?
Ans.It is so because nucleophiles are solvated by polar protic solvents which inhibits it’s ability to participate in Sn2 mechanism.
2. In a reaction where CH3 is nucleophile which one below will proceed faster a) CH3-Br b) CH3-I ?
Ans.The reaction will be faster with CH3-I as I- is good leaving group also it is more stable as compared to Br- as it has less charge density.
3. Why Sn2 reactions prefer primary carbon ?
Ans. It is so because if the carbon is more substituted than due steric hindrance it becomes difficult for nucleophile to attack the substrate.
Any or a monomer can be defined to be a molecule which is responsible to form the basic unit of the polymer where Polymer can be known to be the blocks for protein building.
The function monomers examples are ethylene, glucose, amino acids and vinyl chloride. Functional Monomers are held responsible to get themselves attached with the rest monomers forming a repeating chain of molecules via a known process called polymerization.
The simple sugars are also monomers that are referred to as monosaccharaides. The monosaccharaides have carbon, oxygen and molecules of hydrogen.
Glucose in plants is produced during photosynthesis and is the ultimate fuel for the animals. These also have the capacity to form ling chains which make up the polymers called as carbohydrate that stores energy. Glucose is monomers having six carbons, twelve hydrogen and six oxygen.
The cells also use up glucose for cellular respiration. The rest form of simple sugars includes fructose and galactose. The pentose are also simple sugar like xylose, ribose. On attaching the monomers of sugars produces disaccharides or bigger polymers called polysaccharides.
Made from any monomer, in plants, starch serve as the source of main energy which is insoluble in water. With base being monomers and large number of glucose, this is the process of starch being formed. Animals consumes, grains and many food made have starch in them.
A polysaccharide called glycogen is used for storing energy in animals; the base monomer for it is glucose. The difference between starch and glycogen is that glycogen has more number of branches than starch. If there is any need of extra energy for cells to function, glycogen can be broken down to glucose via hydrolysis.
Cellulose is also an example of it which is found commonly around the globe in plants.Cellulose are the house of a minimum of half of the carbon on earth. On the counts of most animals, they are ineffective in digesting cellulose. It can be only digested by termites and ruminants. Chitin is also an example of polysaccharide which forges the animal shell like crustaceans and insects. The simple monomers of sugar like glucose is thus the basis of any living being and also releases energy for the survival of itself.
Amino Acids
Any subunit of protein is an amino acid. It is the most common polymer which is found in the whole nature. It is thus also a monomer of protein.
Any basic amino acid is made up of an amine group, an R-group, a carboxyl group and a molecule of glucose. There are a total of 20 amino acids present are all of them are used in combinations to make different proteins.
Numerous amino acid join through peptide bonds to create a protein. Two bonded make up dipeptide, three of them combine to form tripeptide and four combine to form tetrapeptide. Following this pattern the protein having more than four amino acids are called polypeptides. Within the 20 amino present. Glucose with amino and carboxyl form the base monomers.
Additional folding of amino acids leads to formation of many complex strictures that are quaternary called collagen. The collagens provide animals with their structure formation. A protein called keratin gives animals’ hair, skin and the features. The proteins also shall be acting as catalysts for several types of reaction in the living body.
These are serving as materials for communication in between the cells. For an instance, a protein called actin plays its role in acting as a transporter for many organisms. The functions of proteins is defined by the three dimensional structure of them.
Nucleotides
For the purpose of amino acid construction, Nucleotides acts as a blueprint which also contains proteins. It is rolled to store data and have energy transfer for the organism.
They are monomers of type linear, natural, nucleic acids like ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). The genetic code of conduct in any organism is carried by DNA and RNA. The monomers of it are made of five carbon sugar, a nitrogenous base and a phosphate.
The bases of the structure include guanine and adenine which are purely derived from purine and then thymine and cytosine or uracil which are from the pyrimidine.
The sugar combined and the nitrogenous bases are held responsible for several functions. One of the common examples is adenosine triphosphate (ATP), which is the main system for energy delivery in organism. ATP molecules are made of ribose, adenine and three groups of phosphate.
The sugar if the nucleic acids are connected together via the phosphodiester linkages. These links carry negative charge which raises a stable macromolecule for the purpose of storing genetic data. The life on Earth has to owe its continuation to the nucleotide monomers which forms the backbone for RNA and DNA and also for ATP.
RNA has ribose, adenine, cytosine and uracil working in several methods inside the cell. RNA is a single helix stricture and also works as an enzyme during DNA replication for making up proteins. On the other hand DNA is more stable with a double helix figure and is the prevalent cell polynucleotide.
A lips which is a polymer also being hydrophobic (repellent to water) is fats. Every monomer has its base and so does fat.
The bases for fats are the alcohol glycerol that has hydroxyl groups with three carbons along with fatty acids. Glucose being a simple sugar yields less energy than fats. Fats release double the energy of glucose. All for these reasons fats serve for energy storage in animals.
Fatty acids that are present in fats as two in number along with one glycerol are known as diacylglycerols or also phsopholipids. The lipids that have three tails of fatty acids and only one glycerol are referred as triacylglycerols. Triacylgylcerols are also popular by fats and oils. A fat are needed by the body to give insulation and also provides nerves its safety inside the body and also the plasma membrane of the cell.
Monomers are surely the essential for being the locks that shall be responsible to build the molecules which make up almost all living and the non-living, all the natural and the man made.
The very most common and vital use of it is its feature of polyfunctionality which is regarded as its capability of forming any chemical bond with two or more rest present molecules of monomers.The term of Monomer while divided into two parts.
The first part being mono means one and the suffix which is mer means part. Monomers are used to categories molecules of various large class which can be very commonly defined into several sub divisions or groups like alcohols, the acrylics, sugars, amines and the epoxides.
How are Monomers named?
The point when there is a combination of few monomers with the polymer, the compounds are given their names.
Dimer- Have two monomers
Trimer- have three units of monomer
Tetramer- Four monomer unit
Pentamer- Five units of monomer
Hexamer- Having six units
Heptamer- Seven units monomer
Octamer- Eights units monomer
Nonamer- Nine monomer units
Decamer- Ten monomers
Dodecamer- 12 units of monomer.
Eicosamer- 20 units of monomer
What are Functional Monomers?
The one that show any specific groups for side chain to get itself reacted and get itself used up for synthesizing more complex compounds for vinyl like macro monomers.
It can also be used to get the functioning of the polymers improved. On the most vital part, these can be used up to trim few features of polymerization and the final residues which takes in to consideration the pros offered by the solvent which interacts with the functional groups.
What are the nature of monomers?
Featuring carbon, polymers which are found sin nature are made of monomers.
An instance of an enzyme that breaks polymer is amylase which also convers starch to sugar. This procedure is also used in digestion. The natural polymers can also be used for thickening, food stabilizing, and emulsification and for medicine. Some examples can be rubber, DNA, keratin, wool and more.
Fatty acids are not considered to be so for there are very few set of chains in lengths that are found in nature and thus for this reason the chains that are numbered in even are more in common that the uneven ones.
Movable pulleys are used in construction cranes, allowing them to lift loads with half the force by balancing weight. Elevators utilize a system of movable pulleys, reducing the motor’s load by 50% for efficient vertical transportation.
A zip line is an exciting activity that involves the use of movable pulleys. Rope-ways gave rise to the idea of zip lining. In mountainous places, rope-ways are commonly used to transport people and objects. Zip lining is a similar activity that may be done in both forest and mountain locations. People’s safety is assured while zip lining by using rope to tie them together.
A person is expected to zip line from the top of the inclined cable to the bottom of the inclined cable by being hooked to the wire or holding it via a freely moving pulley. In this situation, the person acts as the load for the zip lining pulley. As a result, the person is directly attached to the pulley. Gravity assists the speed of the movable pulley’s movement.
Thus, gravity can carry you from one point to another with almost half the effort in zip lining due to the movable pulley. This is how the movable pulley made it possible for the adventurous person.
Construction Equipment:
A movable pulley allows you to lift large objects easily. Because the movable pulley has a mechanical advantage of 2, the effort required to lift a heavy object is nearly half of what it would be if resistance were not taken into account. As a result, if you need to lift a heavy object, the best option is to use a movable pulley. In construction, raw materials must be transported from the ground to the upper floors. As a result, a movable pulley is used there.
A movable pulley is utilized in construction equipment that requires the lifting and dumping of bulky and heavy objects. The pulley is attached to the load you need to transport. One end of a rope that passes through the pulley is fixed, while the other end is used to pull the object. Some construction equipment, such as cranes employ a movable pulley to ease the lifting of heavy objects. Bulldozers use movable pulleys in the same way as cranes do.
Climbing Pulley:
Climbing pulley, as the name implies, is used when you wish to climb anything high, such as a tree or a mountain. The person who wants to climb will act as a pulley load. As the person pulled the other end of the rope, he began to rise high. He goes down on the rope as soon as he stops tugging the rope.
When a person falls down on a rope, it does not indicate that he will fall to the ground because he is already connected to the rope for safety reasons. This is how a movable pulley makes climbing high simpler.
Pulley in Building Wash:
It is vital to keep your building clean and disinfected. You must wash your home and building to keep them clean. A ladder with an easy reach can be used to clean the inside of your home. But what if you want to clean the outside of your high-rise buildings and home? A moveable pulley is utilised for this purpose.
Using a moving pulley, there are two ways to reach the top of the building. In the first situation, a machine such as a crane can be used to reach the top or higher floors that need to be cleaned. Another option is to wash the building in the same manner as tree climbing, with the exception that instead of empty hands, you will need to use a cleaner.
Sliding Doors of bathroom:
Sliding doors are often used at stores, bathrooms, office entrances, hotels, and closet doors as they do not take up more space to open. As the doors are sliding, they use a pulley to accomplish this purpose.
Think about carrying a door and putting it aside. Is it possible to do that? Manually, not, but a movable pulley makes it easy. When you push the door, the pulley moves, and along with the pulley, the door will also move. As the pulley is a movable pulley, the effort we need to slide the door is much less than the effort we need to apply to carry the door from one place to another. The number of movable pulleys used is based on the length of the sliding door.
Anatomical Pulley:
Just like the fixed pulley, a movable pulley is also present in the human body and is called an anatomical pulley. In general, in the human body, bone works as a pulley and the muscle that passes over the bone works as the cord or rope of the pulley. This fact we have already discussed in the fixed pulley examples. So now let us see how a movable pulley works in the human body.
Instead of bone, as in a fixed pulley, muscle itself acts as a pulley in a movable anatomical pulley. The muscle that lays beneath acts as a pulley when two muscles pass over each other. You’re probably asking how this is a movable pulley example. As a result, when the muscle below contracts, the efficiency of the muscle above it increases.So there is no pulley when this muscle is at rest, but when it contracts, it works on the principle of a moving pulley.
Industrial Hydraulic Material Lift Or Cargo Lift:
As we’ve seen, there are a variety of applications for movable pulleys, and one of them is the industrial sector. Yes, movable pulleys are utilised to carry loads in industries.
Movable pulleys make it easier to carry loads from one floor to another in the industrial sector. It may go by different names depending on what it transports, such as oil derricks, hydraulic lifts, or cargo lifts. Basically, the goal is to carry the load with the least amount of effort. It can even transport people from one floor to another.
In an industrial area, by pressing a switch, your hydraulic lift will go from one floor to another. But how does it happen? Here, by pressing the switch, you are basically pulling the rope which is passing over the pulley. And with the electric force, the lift and the load that it carries also go from one floor to another.
Frequently Asked Questions (FAQs):
Q. What is pulley?
Ans: The pulley is basically a simple machine.
The pulley is nothing more than a wheel with a grooved rim that holds a cord, rope, belt, or chain. Pulleys can offer either direction orforce multiplication, or both at the same time.
Q. What are the different types of pulleys? Describe each type in brief.
Ans: There are three main types of pulley, which are given below:
Fixed pulley: A fixed pulley has a supported axis of rotation with a bearing. In short, the axis of rotation can not change with the movement of the load. As the force you need to pull the load is not decreased using this pulley, we can say that it does not provide mechanical gain. The pulleys used in flagpoles and water wells are the common examples of a fixed pulley.
Movable pulley: The axis of rotation of a movable pulley is not fixed like that of a fixed pulley. It indicates that it changes as the load moves. Because the load is carried by two segments of a single rope via a moveable pulley, it has twice the mechanical advantage of a fixed pulley. When a heavy load needs to be carried, a movable pulley should be employed. Pulleys used in zip lining, cargo lifts, and construction equipment are examples of movable pulleys.
Compound Pulley: When a fixed and movable pulley are used together to improve mechanical advantage, it is referred to as a compound pulley. It’s also known as a block and tackle system or a combination pulley. Compound pulleys can be seen in sailboats and elevators.
Q. What is the difference between the working of a fixed pulley and a movable pulley?
Ans: When lifting a heavy object, both fixed and mobile pulleys are employed.
The amount of effort required to lift an object with or without a fixed pulley is the same. Only the direction in which effort is applied has changed. When a movable pulley is used to lift a heavy object, the direction of application of effort remains the same, but the amount of effort is decreased by half.
Changes that occur only in one direction or changes that are permanent are known as irreversible chemical changes.
Irreversible chemical change examples include much day- to- day work like cooking, eating, digesting, etc. Burning of fire-crackers, combustion, rusting, leaves changing color, decomposition of food are also some irreversible chemical change examples that we observe frequently.
When an irreversible chemical change occurs, internal properties of material change. Properties like boiling point, melting point, molecular mass, color, odor, etc., change.
Combustion of fuel is an irreversible chemical change example. In this type of reaction, the fuel combines with oxygen in the air and emits products such as carbon dioxide and water vapor.
The direction of the arrow is only in one way, which coveys that the reaction is irreversible.
Combustion of fuel is as simple an example as burning of wood or baking a cake. Once the wood turns to ashes, the ashes cannot be turned into wood again; likewise, once the cake is baked; we cannot un-bake the cake. Cake cannot be transformed back into flour, egg, sugar, etc.
Similarly, in the above chemical process, the reaction between carbon dioxide and water cannot create fuel and oxygen.
The ripening process of any fruit or vegetable is considered as an irreversible chemical change example as once the fruit is ripened, it cannot be reversed as a raw fruit. Though the ripening of fruits and vegetables is not an entirely chemical process, it is a bio-chemical change.
As a bio-chemical change, numerous enzymes, genes, and acids work together, breaking and making chemical bonds to alter the fruit and vegetable from being raw to ripe. Chiefly, ethylene gas is responsible for ripening of fruits and vegetables and is often referred to as the ‘Food Ripening Hormone.’
In the above image, the extreme left green – colored banana is the raw banana and the extreme right yellow banana with brown spots indicates ripened banana.
Every so often, we hear that raw fruits and vegetables have different advantages as well as disadvantages from ripened fruits and vegetables. Sometimes, unripe fruits and vegetables have better health benefits than ripe fruits and vegetables.
The Process of Turning Milk into Curd
The best irreversible chemical change example is the formation of curd from milk. It is effortless to make curd. Heat the milk until it is lukewarm and then add a drop or two of either buttermilk or lemon juice. Set it overnight and the following morning, the curd is ready.
This process is called curdling. When an edible acidic substance is added to milk, the milk thickens, forming curd. Thickening, also known as coagulation, gives curd its thick quasi-solid appearance.
In scientific language, when lactose reacts with water, it produces lactic acid. Lactose is a substance present in milk which is also known as the ‘Milk Sugar.’ The sour taste of curd is a result of lactic acid.
The equation for the conversion of lactose to lactic acid is given as:
Another fine and important irreversible chemical change example is the rusting of iron. When iron associates with oxygen in the presence of moisture, it forms iron oxide and starts to rust. This reaction is well known as a redox reaction. In a redox reaction, one substance undergoes oxidation while the other undergoes reduction, and thus, the reaction is called a redox reaction.
Iron becomes crumbly and reddish-brown when rusted. Iron can be prevented from rusting but once rusted; it cannot be brought back to its original form.
The reaction between an acid and a base is popularly known as neutralization. Here, let us take an example of ammonium bromide and potassium amide. Where ammonium bromide is an acid and potassium amide is a base. The reaction between an acid and a base invariably yields salt.
Salt is a neutral compound and in this case, potassium bromide is a salt. Acid is known for either donating its proton or for making covalent bonds. Here, it is a clear case of donating its proton.
Acids are wet or sticky and taste sour, while bases are slippery to touch and taste bitter.
One excellent example for both an acid and a base that we use in our regular life is vinegar, which is an acid, and baking soda, which is a base. These products are weak acids and bases. Other than a few regular products, one shouldn’t touch an acid or a base directly as they can damage the skin.
Growth of Plants and Animals
The growth of plants and animals isn’t an entirely chemical process; again, it is a mixture of biological changes as well as chemical changes, and thus, we call it a bio-chemical change. As described above, in the section – ripening of fruits and vegetables, various enzymes, organisms, chemicals work together for the growth of the body. Human beings, too, come under this category.
The process of cooking, eating, digesting and body converting that food into energy all these processes come under irreversible change. Unlike humans, animals don’t cook, but they do eat and digest. Their body converts the food into energy just like ours!
Plants have a whole other system of obtaining energy from water and sunlight. They use the light received from the sun to perform photosynthesis, make fruits, flowers, and vegetables and produce oxygen.
All these processes are excellent irreversible chemical change examples. Most of them occur in our day- to- day life, while others can be observed in laboratories.
