In this article, we will study the various types of periodic motion examples and their detailed explanations.
A type of motion that exhibits a cyclic process or repeats the same cycle after the same time intervals. Earth revolving around the sun for every 365 days is the best example of periodic motion. Simple harmonic motion is a common and well-known type of periodic motion.
In the upcoming section, let us discuss the different examples of periodic motion in
Simple harmonic motion is the most studied periodic motion. In a system with no resistive force (ideal system or under ideal conditions), the motion is not acted by any damping effect; thus, it takes place again and again in regular intervals of time, i.e., it’s a periodic motion. An oscillating pendulum depicts the simple harmonic type of motion.
With a fixed time interval, the pendulum performs a continuous to and fro motion, or it is said to undergo a constant swinging movement. Observed the pendulum to be passing through a mean position or an extreme position after a fixed interval of time. Since, in this case, the motion repeats after the same period, it is an example of periodic motion.
It is also termed a rocker. The rocking chair is a type of chair that possesses curved ends at the bottom, which enables the person to move back and forth by just shifting their weights; this movement creates a rocking effect, and the motion is periodic; hence it depicts the periodic type of motion.
As already mentioned, the earth revolves around the sun. To complete one revolution, the earth needs 365 days and 6 hours. This motion of the earth around the sun keeps repeating; this is an interpretation of periodic motion because it is not affected by any restoring force such as friction.
Along with revolving around the sun, it also rotates about its axis every 24 hours; this is a continuous motion retaking place after every 24 hours, which implies that it is a periodic motion having no restoring force acting on it. Hence, it can be taken as an example of periodic motion.
Revolution of an electron
Around a positively charged nucleus, the electron is said to revolve without any disturbance due to friction in a periodic manner. Thus it’s a periodic motion repeated repeatedly in a certain period.
We know that the earth similarly revolves around the sun; the moon is also said to be revolving around the earth, not being acted by any force that would interrupt the motion. Both the motions are identical and are found to be repeating after a specific interval of time.
Tuning fork
A tuning fork is a U-shaped instrument usually made of steel (or any other elastic metal). When it is sriked against a surface, it starts vibrating, resonating with a constant pitch. Such exhibited vibrations are periodic. Hence it shows a periodic motion.
Rotating hub and blades constitute a propeller forming a helical spiral shape. The set-up is set to rotate at a pitch and is considered a periodic motion. The propeller is generally used to exert a thrust on the fluids like water or air so that it is possible to pump fluid through a pipe. It is widely used in the boat’s movement in the water or an aircraft through the air.
Hands in a clock
The needles or hands in a clock cover a complete rotation of 360 degrees in a fixed interval which is the cause for the calculation of time. Since this rotation of the hands is continuous repeatedly, this is an instance of periodic motion as there is no friction in the motion.
On average, 60 to 100 beats are constantly seen in a normal heart in one minute. An abnormality is said to occur if the heartbeat is not even. As the heartbeat counts are constant per minute, it is periodic.
Frequently asked questions | FAQS
What is the reason for a periodic motion to happen?
The motion to be periodic the system has to be governed by a law or theory.
Newton’s first law (law of inertia) explains that the object moves without interruption when not acted by any external force; this also holds good for the concept of periodic motion.
For example, When an oscillating pendulum is lifted from its mean position, it continues to swing from the extreme position to the mean position repeatedly uninterrupted in a periodic fashion. There is no implication of force.
What makes a simple harmonic motion to be periodic?
The simple harmonic motion shows some of the criteria that make it a periodic motion.
In a system with no resistive force (ideal system or under ideal conditions), the motion is not acted by any damping effect. Thus the motion takes place again and again in a regular interval of time, i.e., it starts oscillating back and forth across the mean position, and it’s a periodic motion.
Simple harmonic motion is the most studied periodic motion. An oscillating pendulum depicts the simple harmonic type of motion. A sinusoidal wave motion perfectly interprets the harmonic motion, a periodic motion.
What do you mean by frequency in a periodic motion?
Frequency is one of the parameters to define or understand a particular type of motion.
In general, frequency is referred to the total number of times the motion takes place, or it gets repeated in a time interval of one second. A generally used basic unit to describe the frequency of an object is hertz.
The time period is also a vital parameter to gain information about a motion. Frequency and time period are related to each other in an inverse manner.
A cup of hot tea at 80°C placed in a 20°C room reaches thermal equilibrium when both the tea and surrounding air stabilize at a mid-range temperature, say 25°C, due to heat transfer. This follows the Zeroth Law of Thermodynamics, where if two systems are in thermal equilibrium with a third, they are in equilibrium with each other. The rate of heat exchange is proportional to the temperature difference, as per Fourier’s law of heat conduction.
The surrounding air molecules are convenient thermal equilibrium examples because the air molecule attains the temperature same as the surrounding temperature and is in equilibrium with nature. The surrounding temperature is transferred to the air molecule to balance the temperature.
Hot water in a thermos flask
Thermos flasks are isolated systems, so there will be no flow of heat out of the system. This is one of the good thermal equilibrium examples when the hot water is poured into the flasks. The temperature of the water is transferred to the flasks; thus, the equilibrium is established between the flasks and the water. When you open the lid of the flasks, the stream of water rushes out is because of the balance of thermal equilibrium.
If you pour a hot coffee into the cold cup, the cup becomes hot same as the coffee. The hotness of the coffee is transferred to the cup; thus, the coffee is in equilibrium with respect to the cup by transferring its temperature to the cup.
When automobiles are driven for a long time, the engine gets heated. As the automobile is retard from the motion and is under a stationary state, after some time, the engine cools down, and its temperature becomes equal to the surrounding temperature; thus, the state of equilibrium is attained by the engine with respect to the surrounding temperature.
Electronic devices
All electronic devices heated up while running. This heat is not permanent. The devices cool down after some time to be in equilibrium with the surrounding environment, thus satisfying the thermal equilibrium condition.
Products kept in the fridge.
If you keep any product overnight inside the refrigerator, it becomes cool. In this case, the coldness of the refrigerator is making the product cool. Thus the temperature of the refrigerator and the product will be the same. Hence the thermal equilibrium is generated between the refrigerator and the product.
If you hold any marble for a long time, the temperature of your hand and the marble will be equal. This can be well defined as the marble is in thermal equilibrium with the hand as the temperature of the hand is transferred to the marble until it becomes equal. Thus holding a marble in hand is one of the best thermal equilibrium examples.
Take a glass of water at room temperature and put some ice cubes in the same water. The ice gradually melts by exchanging its temperature with water. The exchange of the temperature between the water and the ice cubes takes place until both water and ice attain the same temperature, thus satisfying the equilibrium condition.
If you keep the ice cream out of the refrigerator for some time, it interacts with the surroundings, and a transfer of heat will occur. The ice cream melts until its temperature matches the surrounding temperature. Thus ice cream will be in equilibrium with the surrounding satisfying the thermal equilibrium.
Butters are very sensitive to temperature. When the butter comes into contact with different temperatures, the butter melts and tries to be in equilibrium with the surrounding. Thus melting the butter is one of the excellent thermal equilibrium examples.
Formation of Glaciers
At the poles, the permanent glaciers in the sea are one of the natural thermal equilibrium examples. Due to global warming, the temperature near the sea increases rapidly; thus, the ice melts, creating glaciers. The glaciers are in thermal equilibrium with the sea near the poles.
If you have a fever, you will check your body’s temperature using a thermometer. In this case, your body temperature is transformed to a thermometer consisting of mercury. As the heat is supplied, the mercury begins to rise until your body temperature, and the mercury becomes equal. When both the temperature becomes the same, there will be no transfer of heat from the body, and the rising mercury is also stopped. The point where the mercury has stopped its motion is recorded as your body’s temperature.
When the contact between your body and the thermometer is removed, the mercury begins to move downward and settles at its original position until it reaches zero. In both cases, the mercury is in equilibrium with the given surrounding. Before coming into contact with your body, the thermometer is in balance with the surrounding environment. When it comes to your body contact, the thermal equilibrium is set between the thermometer and your body. Once released from your body contact, the thermometer will attain equilibrium with the surrounding once again.
Human body
The human body, after death, will become cold is due to the thermal equilibrium. There will be a transfer of heat between the body, and the surrounding takes place to balance the temperature. This process takes only for little time after death to achieve thermal equilibrium.
The hand kept on a cold rail.
If you keep your hand on a cold rail, your hands get cold. The coldness of the rail is transferred to your hand to balance the temperature. Once the temperature of your hand and the rail becomes the same, the thermal equilibrium between the rail and hand is achieved.
Have you ever entered the AC room? If you have, then you have experienced your body becoming cold or hot depending on the temperature of the AC sets. Your body achieves the same temperature as the AC as you enter the room. Thus thermal equilibrium is set up between you and the room.
Mixing hot and the cold water
When you mix the hot water and the cold water, the hot water transfer its temperature to cold water, and the cold water gives its coldness to the hot water; thus, the exchange of temperature between them take place. This process takes place until no heat is left to exchange; thus, thermal equilibrium is generated.
Hydrates are compounds that contain water molecules within their crystal structure. They are formed when water molecules are trapped within the lattice structure of a solid compound. Hydrates can be found in various forms and have a wide range of applications. Some common examples of hydrates include copper sulfate pentahydrate, which is used in agriculture and as a fungicide, and magnesium sulfate heptahydrate, which is used in medicine and as a drying agent. Other examples include sodium carbonate decahydrate, which is used in cleaning products, and calcium sulfate dihydrate, which is used in food and pharmaceutical industries.
Key Takeaways
Compound
Chemical Formula
Common Uses
Copper sulfate pentahydrate
CuSO4·5H2O
Agriculture, fungicide
Magnesium sulfate heptahydrate
MgSO4·7H2O
Medicine, drying agent
Sodium carbonate decahydrate
Na2CO3·10H2O
Cleaning products
Calcium sulfate dihydrate
CaSO4·2H2O
Food, pharmaceutical industries
Understanding Hydrates
Hydrates are compounds that contain water molecules within their crystal structure. These water molecules are known as water of hydration or water of crystallization. The process of water molecules binding to a compound is called hydration. Hydrates can form when certain compounds come into contact with water or when water vapor condenses onto a solid surface.
Explanation of Hydrates
In chemistry, hydrates are formed when water molecules are incorporated into the crystal lattice of a compound. This occurs through a hydration reaction, where the compound and water molecules chemically bond together. The resulting compound is called a hydrate.
Hydrates can have different structures depending on the compound involved. Some hydrates have a specific ratio of water molecules to the compound, while others can vary in the number of water molecules they can accommodate. The structure of hydrates is determined by the arrangement of the compound and water molecules within the crystal lattice.
Hydrate Equations Examples
To understand hydrates better, let’s take a look at some examples of hydrate equations:
Copper(II) sulfate pentahydrate: CuSO4 · 5H2O
This equation represents copper(II) sulfate with five water molecules bound to it.
Magnesium sulfate heptahydrate: MgSO4 · 7H2O
This equation represents magnesium sulfate with seven water molecules bound to it.
Calcium chloride dihydrate: CaCl2 · 2H2O
This equation represents calcium chloride with two water molecules bound to it.
Hydrate Calculation Examples
Calculating the amount of water in a hydrate can be done using the following steps:
Determine the molar mass of the hydrate compound.
Determine the molar mass of the anhydrous compound (without water).
Subtract the molar mass of the anhydrous compound from the molar mass of the hydrate compound to find the molar mass of water.
Calculate the moles of water by dividing the mass of water by its molar mass.
Calculate the moles of the anhydrous compound by dividing its mass by its molar mass.
Determine the ratio of moles of water to moles of anhydrous compound.
Hydrate Formula Examples
Hydrate formulas represent the composition of hydrates by indicating the number of water molecules per formula unit of the compound. Here are some examples:
Copper(II) sulfate pentahydrate: CuSO4 · 5H2O
This formula indicates that for every formula unit of copper(II) sulfate, there are five water molecules.
Magnesium sulfate heptahydrate: MgSO4 · 7H2O
This formula indicates that for every formula unit of magnesium sulfate, there are seven water molecules.
Calcium chloride dihydrate: CaCl2 · 2H2O
This formula indicates that for every formula unit of calcium chloride, there are two water molecules.
Hydrates play a significant role in various fields, including chemistry, geology, and materials science. They can be found in nature, such as in minerals like gypsum, and they also have practical applications, like in the formation of gas hydrates for energy storage. Understanding hydrates and their properties is essential for studying their behavior and exploring their potential uses.
Types of Hydrates
Hydrates are compounds that contain water molecules within their crystal structure. These water molecules are known as “water of hydration” and are held in place by intermolecular forces. There are different types of hydrates, each with its own unique characteristics and examples.
Hydrate Compound Examples
Hydrate compounds are formed when water molecules are incorporated into the crystal lattice of a compound. This results in the formation of a hydrate with a specific chemical formula. Some examples of hydrate compounds include:
Methane Clathrate: Methane clathrate, also known as methane hydrate, is a type of gas hydrate where methane molecules are trapped within a lattice of water molecules. It is found in deep-sea sediments and permafrost regions and has gained attention as a potential future energy resource.
Gypsum: Gypsum is a mineral that can form hydrates. Its chemical formula is calcium sulfate dihydrate (CaSO4·2H2O), indicating that it contains two water molecules per formula unit. Gypsum is commonly used in construction materials and as a soil amendment.
Hydrate isomers are compounds that have the same chemical formula but different arrangements of water molecules within their crystal structure. This results in distinct physical and chemical properties. Some examples of hydrate isomers include:
Methane Hydrate: Methane hydrate can exist in different isomeric forms depending on the arrangement of water molecules. These isomers can have varying stability and gas storage capacities.
Salt Hydrate: Salt hydrates, such as sodium sulfate decahydrate (Na2SO4·10H2O), can have different isomeric forms based on the arrangement of water molecules. These isomers may exhibit different solubilities and thermal properties.
Ionic Hydride Examples
Ionic hydrides are compounds that consist of hydrogen ions (H-) and other ions. These hydrides can be formed through various chemical reactions and have unique properties. Some examples of ionic hydrides include:
Sodium Hydride: Sodium hydride (NaH) is an ionic hydride that is commonly used as a reducing agent in organic synthesis. It reacts with water to produce hydrogen gas and sodium hydroxide.
Calcium Hydride: Calcium hydride (CaH2) is another example of an ionic hydride. It is used as a drying agent and can react with water to release hydrogen gas.
Examples of Hydrates
Hydrates are compounds that contain water molecules within their crystal structure. They form when water molecules become trapped within the lattice of a solid compound, resulting in a hydrated form of the compound. Here are some examples of hydrates:
Gypsum
Gypsum is a common hydrate that is widely used in construction materials. Its chemical formula is CaSO4·2H2O, indicating that each calcium sulfate molecule is associated with two water molecules. Gypsum is known for its use in creating plaster and drywall.
Borax
Borax, also known as sodium borate, is a hydrate with the chemical formula Na2B4O7·10H2O. It is commonly used as a cleaning agent and in the production of glass and ceramics. Borax forms large crystals that contain ten water molecules per unit.
Epsom salt, scientifically known as magnesium sulfate heptahydrate (MgSO4·7H2O), is a well-known hydrate used for various purposes. It is often used in bath salts and as a natural remedy for muscle aches and pains. Epsom salt crystals contain seven water molecules per unit.
Glauber’s Salt
Glauber’s salt, or sodium sulfate decahydrate (Na2SO4·10H2O), is another example of a hydrate. It is used in the manufacturing of detergents, glass, and paper. Glauber’s salt crystals contain ten water molecules per unit.
Washing soda, also known as sodium carbonate decahydrate (Na2CO3·10H2O), is a hydrate commonly used as a cleaning agent and water softener. It is often used in laundry detergents and household cleaning products. Each unit of washing soda contains ten water molecules.
Cobalt Chloride
Cobalt chloride is a hydrate with the chemical formula CoCl2·6H2O. It is commonly used as an indicator for humidity and moisture levels. Cobalt chloride crystals contain six water molecules per unit.
Copper sulphate, or cupric sulfate pentahydrate (CuSO4·5H2O), is a hydrate used in various applications, including agriculture, electroplating, and as a fungicide. Copper sulphate crystals contain five water molecules per unit.
Beryllium Sulphate
Beryllium sulphate is a hydrate with the chemical formula BeSO4·4H2O. It is used in the production of ceramics and as a catalyst in organic synthesis. Beryllium sulphate crystals contain four water molecules per unit.
These examples illustrate the diverse range of hydrates found in various industries and everyday applications. The presence of water molecules within these compounds not only affects their physical properties but also plays a crucial role in their chemical behavior.
Potassium Carbonate
Potassium carbonate is a chemical compound that is commonly used in various industries and applications. It is an inorganic salt with the chemical formula K2CO3. This compound is known for its ability to react with water and form hydrates, which are compounds that contain water molecules within their crystal structure. In this section, we will explore the role of potassium carbonate in the formation of hydrates, specifically focusing on its interaction with ethanol.
Ethanol
Ethanol, also known as ethyl alcohol, is a colorless and flammable liquid that is commonly used as a solvent, fuel, and in the production of alcoholic beverages. When ethanol comes into contact with potassium carbonate, it can undergo a hydration reaction, leading to the formation of a hydrate compound.
Hydration reactions involve the addition of water molecules to a substance, resulting in the formation of a hydrate. In the case of ethanol and potassium carbonate, the reaction can be represented as follows:
K2CO3 + C2H5OH + H2O → K2CO3·C2H5OH·H2O
The resulting compound contains potassium carbonate, ethanol, and water molecules within its crystal structure. This type of hydrate is an example of a chemical hydrate, where water molecules are incorporated into the compound.
Hydrates can have different structures depending on the specific compound involved. In the case of potassium carbonate and ethanol, the hydrate structure consists of potassium carbonate ions, ethanol molecules, and water molecules arranged in a specific pattern.
Potassium carbonate can also form hydrates with other substances, such as gases. Gas hydrates are solid compounds that contain gas molecules trapped within their crystal lattice. One well-known example is methane hydrate, where methane molecules are enclosed within a lattice structure formed by water molecules.
In addition to its role in hydrate formation, potassium carbonate is used in various other applications. It is commonly used in the production of glass, as a pH regulator in the food industry, and as a drying agent in laboratories. It also finds applications in the manufacturing of soaps, detergents, and fertilizers.
Hydrates in Everyday Life
Hydrates are compounds that contain water molecules within their structure. They play a significant role in our everyday lives, from the food we eat to the products we use. Let’s explore some examples of hydrates in various aspects of our daily lives.
Examples of Hydrates in Everyday Life
Gypsum: Gypsum is a commonly used hydrate in construction materials. Its chemical formula is CaSO4·2H2O, which indicates that it contains two water molecules per calcium sulfate molecule. Gypsum is used in the production of plasterboard and cement, contributing to the strength and durability of these materials.
Epsom Salt: Epsom salt, also known as magnesium sulfate heptahydrate (MgSO4·7H2O), is a hydrate commonly used for its therapeutic properties. It is often added to bathwater to help relax muscles and relieve stress. The seven water molecules in its structure contribute to its ability to dissolve easily in water.
Copper Sulfate Pentahydrate: Copper sulfate pentahydrate (CuSO4·5H2O) is a blue crystalline hydrate used in various applications. It is commonly used as an agricultural fungicide, a laboratory reagent, and in the production of pigments and dyes. The five water molecules in its structure help stabilize the compound and enhance its solubility.
Regularly Used Hydrates
Apart from the specific examples mentioned above, there are several hydrates that we encounter regularly in our daily lives. Here are a few commonly used hydrates:
Sodium carbonate decahydrate (Na2CO3·10H2O): This hydrate, also known as washing soda, is used in laundry detergents and household cleaning products.
Calcium chloride dihydrate (CaCl2·2H2O): Calcium chloride dihydrate is used as a drying agent, de-icer, and in the food industry for cheese making.
Sodium bicarbonate monohydrate (NaHCO3·H2O): Commonly known as baking soda, this hydrate is used in baking, cleaning, and as an antacid.
Hydrates in Food and Drinks
Hydrates are also present in various food and drinks that we consume. Here are a few examples:
Sugar: Common table sugar, or sucrose, is a hydrate. Its chemical formula is C12H22O11·H2O, indicating the presence of one water molecule per sucrose molecule. This water molecule contributes to the crystalline structure of sugar.
Honey: Honey is a natural sweetener that contains water molecules as hydrates. The exact composition of honey can vary, but it typically contains around 17-20% water.
Fruits and Vegetables: Many fruits and vegetables have a high water content, making them hydrating foods. Watermelon, cucumber, and oranges are examples of hydrating fruits and vegetables that provide both hydration and essential nutrients.
Hydration and Health
Hydration is essential for maintaining good health. It plays a crucial role in various bodily functions, including regulating body temperature, lubricating joints, and transporting nutrients. Proper hydration is especially important during physical activity or in hot weather when the body loses water through sweat. In this article, we will explore different aspects of hydration and discuss the liquids that hydrate you the most, other than water, and the best options for staying hydrated.
What Liquid Hydrates You the Most
When it comes to hydration, water is often considered the gold standard. It is readily available, calorie-free, and helps replenish the body‘s water content effectively. Water is easily absorbed by the body, allowing for quick rehydration. However, there are other liquids that can also provide hydration.
Sports drinks are commonly used by athletes and individuals engaging in intense physical activity. These drinks contain electrolytes, such as sodium and potassium, which help replenish the body‘s electrolyte balance. While sports drinks can be beneficial during prolonged exercise, they may not be necessary for everyday hydration.
Coconut water is another popular choice for hydration. It is a natural source of electrolytes and contains potassium, magnesium, and calcium. Additionally, coconut water is low in calories and has a refreshing taste, making it a great option for those looking for a hydrating beverage with a hint of flavor.
What Hydrates You Other Than Water
While water is the go-to choice for hydration, there are other liquids that can contribute to your daily fluid intake. Some examples include:
Herbal teas: These teas are made from various plants and herbs, such as chamomile, peppermint, or ginger. They can be enjoyed hot or cold and provide hydration along with potential health benefits from the herbs.
Fruit juices: Juices made from fruits like oranges, watermelons, or grapes can contribute to hydration. However, it’s important to choose juices without added sugars and consume them in moderation due to their natural sugar content.
Milk: Milk is not only a good source of hydration but also provides essential nutrients like calcium and protein. It can be consumed plain or used as a base for smoothies and shakes.
What Hydrates You the Best
While water remains the top choice for hydration, the best way to stay properly hydrated is to consume a variety of liquids throughout the day. This ensures that you not only replenish your body’s water content but also obtain essential nutrients from different sources.
It’s important to note that certain factors can affect hydration levels, such as physical activity, climate, and individual needs. If you engage in intense exercise or spend time in hot weather, you may need to increase your fluid intake to compensate for the additional water loss.
Glauber’s Salt, also known as sodium sulfate decahydrate, is a chemical compound that belongs to the group of hydrates. In its hydrated form, Glauber’s Salt contains ten water molecules per formula unit. This compound is commonly used in various industries, including the detergent and textile industries. It is also used in some medical applications and as a laxative.
Determine the Number of Water Molecules in Hydrated Form of Potassium Carbonate
To determine the number of water molecules in the hydrated form of potassium carbonate, you need to know the chemical formula of the compound. In this case, the hydrated form of potassium carbonate is known as potash alum. Its chemical formula is KAl(SO4)2·12H2O. Therefore, there are twelve water molecules associated with each formula unit of potash alum.
Use of Epsom Salt
Epsom salt, scientifically known as magnesium sulfate heptahydrate, is a commonly used hydrate. It is widely used for its therapeutic properties, particularly in bath salts and foot soaks. Epsom salt can help relax muscles, reduce inflammation, and relieve minor aches and pains. It is also used as a fertilizer in gardening to provide magnesium and sulfur to plants.
Example of Regularly Used Hydrate
One example of a regularly used hydrate is copper sulfate pentahydrate. Its chemical formula is CuSO4·5H2O, indicating that each formula unit of copper sulfate pentahydrate is associated with five water molecules. This compound is often used in agriculture as a fungicide and herbicide. It is also used in laboratories for various chemical reactions and as a coloring agent in dyes and pigments.
What is Gas Hydrate and Its Chemical Formula
Gas hydrates are a type of hydrate where gas molecules are trapped within a lattice structure formed by water molecules. The most well-known gas hydrate is methane hydrate, which consists of methane gas molecules trapped within water ice crystals. Its chemical formula is CH4·6H2O. Gas hydrates are found in abundance in nature, particularly in deep-sea sediments and permafrost regions. They have gained significant attention due to their potential as a future energy resource.
Frequently Asked Questions
What is a hydrate and why are hydrates important in chemistry?
A hydrate is a compound that includes water molecules within its structure. Hydrates are important in chemistry because they can alter the physical and chemical properties of substances. They are crucial in many chemical reactions and processes, including hydration reactions and hydrate formation.
Can you give an example of a hydrate in everyday life?
Yes, an example of a hydrate in everyday life is Gypsum, a commonly used material in construction. Its chemical formula is CaSO4.2H2O, indicating it is a hydrate with two water molecules attached to each formula unit.
What is the difference between anhydrous and hydrate compounds?
Anhydrous compounds are substances that do not contain water molecules within their structure, while hydrate compounds do. For example, copper sulfate is a hydrate when it contains water (CuSO4.5H2O), but it becomes anhydrous when the water is removed (CuSO4).
What is the chemical formula for a hydrate?
The chemical formula for a hydrate includes the formula of the anhydrous compound followed by a dot and the number of water molecules per formula unit. For example, the chemical formula for copper sulfate pentahydrate is CuSO4.5H2O.
What is a gas hydrate and can you provide an example?
A gas hydrate is a type of hydrate where a gas molecule is encased within a cage of water molecules. An example is Methane hydrate, where methane gas is trapped within a lattice of water molecules. This is commonly found in deep-sea sediments.
How do hydrates form?
Hydrates form when water molecules become integrated into the crystal structure of a substance. This usually occurs during crystallization, where the substance and water are combined in a solution and the water becomes incorporated as the solution cools and solidifies.
What is the role of water in hydrate compounds?
Water plays a crucial role in hydrate compounds. It is integrated into the crystal structure of the compound, often affecting its physical and chemical properties. The water in hydrates can also participate in chemical reactions.
What are some examples of hydrate minerals?
Hydrate minerals are minerals that contain water in their crystal structure. Examples include Gypsum (CaSO4.2H2O) and Epsom salt (MgSO4.7H2O).
How can you determine if a compound is a hydrate?
You can determine if a compound is a hydrate by heating it. If it is a hydrate, it will lose water and the mass will decrease. This process is called dehydration. The change in mass can be used to calculate the number of water molecules in the hydrate.
How are hydrates used regularly in chemistry?
Hydrates are used regularly in chemistry in various ways. They are used in the preparation of other compounds, in chemical reactions, and in the study of crystal structures. They are also used in industries such as construction and agriculture, in products like cement and fertilizers.
Displacement reaction examples take place when a reactant is replaced by other reactant. This research is going to represent detailed explanations of the examples of Displacement reaction.
There are some effective Displacement reactions examples are listed below:
Example 1: Single displacement reaction
In this single displace reactions only one of the reactants release the ion and replaces the other reactant with the formation of a new compound.
The reaction between Iron and Copper sulphate is a perfect and simplest example of single displacement reaction. Here copper sulphate releases the sulphate ion and it gets added to Iron metal and gives out ferrous sulphate and Cu metal.
Equation:
Fe + CuSO4 = FeSO4 + Cu
Besides, when Zinc metal reacts with Hydrochloric acid a single displacement reaction can be noticed to be happened. In this reaction Zinc Chloride forms as chloride ion adds on with the zinc metal. Bubbles forms in the reaction which indicates the formation of hydrogen gas.
Equation:
Zn + 2HCl = ZnCl2 + H2
Another effective example of single displacement reaction could be explained that is the reaction between ferric oxide and Coke. Coke is replaces with Carbon Dioxide and free Fe metal has been obtained as product.
When two salts reacts with each other and both the reactants are replaced by each other such as the positive and negative ions are exchanged by each other, that type of replacement reaction is called Double displacement reaction.
The reaction between sodium sulphide and hydrochloric acid gives out Sodium chloride and hydrogen sulphide. Here sodium sulphide trades its sulphide ion to HCl and HCl trades its Chloride ion to Sodium sulphide.
Equation:
Na2S + 2HCl = 2NaCl + H2S
Besides, when silver nitrate reacts with sodium chloride they exchange their anions and give out silver chloride and sodium nitrate. It is an example of precipitation reaction as well. AgCl has been identified to be precipitated here.
Double displacement reaction examples from Wikipedia
The reaction between Barium chloride and Sodium sulphate gives out barium sulphate precipitate and sodium chloride.
Equation:
BaCl2 + 2NaSO4 = Ba(SO4)2 + 2NaCl
Example 3: Displacement reaction examples based on reactivity of elements
Displacement reaction happens by depending on the reactivity of the metals. More reactive metals easily replace the less reactive metals from the compounds. This is the main reason behind the displacement reaction.
When lead is made to react with copper chloride it gives out lead chloride and free copper metal. As lead is more reactive than copper it easily breaks the bond between copper and chloride ion.
Equation:
Pb + CuCl2 = PbCl2 + Cu
Another example can be described by mentioning the reaction between Zinc and Copper sulphate. It reactive zinc becomes successful in extracting sulphate ion from Copper sulphate mad gives out Zinc sulphate.
Equation:
Zn + CuSO4 = ZnSO4 + Cu
Example 4:Acid-base reactions
The Neutralization reactions between Acid and Bases are considered to be great displacement reaction examples. When an acid neutralizes a base, the replacement of ions among acids and bases takes place and support the principle of displacements reaction. Double displacement reaction takes place here anyway.
For an example, when hydrochloric acid reacts with potassium hydroxide, it neutralises the base and reaches out to a certain neutral kevel of pH, the replacement of hydrochloric acid trades its chloride ion to potassium and gives out the natural salt potassium chloride.
Table salt formation follows the same principle as the above one. NaCl is called table salt generally. When strong Hydrochloric acid reacts with strong base sodium hydroxide it produces table salt and water.
Rusting is the best example of oxidation reaction as a well as the displacement reaction. When things made of iron metal are kept into open air the oxygen gas oxidise the Iron metal and a reddish brown layer is formed by the as the effect.
In this reaction the metal (Iron) is replaced by the action of oxygen gas and through this displacement reaction rust forms that is Fe2O3, H2O. The moist air is the reason behind oxidising the metal ions.
Rusting occurs as displacement reaction examples from Wikimedia
As this oxidation reaction occurs through replacement of metal with its oxide, this reaction is considered as one of the practical displacement reaction examples.
Example 6: The reaction of baking soda and vinegar
The reaction of baking soda and vinegar is one of the best examples of displacement reaction. This reaction happens in two steps, the first reaction is the reference of double displacement reaction.
Acetic acid present in vinegar reacts with sodium carbonate in baking soda. This reaction happens through replacement of both acetic acid and carbonate. Therefore, it is happened by maintaining the principles of double displacement reaction.
Reaction between Vinegar and baking soda from Wikipedia
The products come out from the reaction are Sodium acetate and carbonic acid. The unstable carbonic acid then decomposes and the next reaction takes place as decomposition reaction.
Single displacement reaction happens in photosynthesis process. This is the main process of making food of the plants. Single displacement reaction takes place during Calvin cycle. In the light reaction when hydrogen molecules get separated from the water molecule to replace the carbon dioxide molecules to form the Glucose.
Double displacement reaction takes place in cellular respiration. This is not a single reaction. Both oxidation and reduction reactions are noticed to be take place here. Therefore, it is it is a great example of redox reaction.
On the other hand, this reaction is reliable I absorbing exergonic reaction properties. That is it releases a certain amount of energy with the products. The double displacement properties can be shown in cellular respiration as well.
When glucose is oxidised and oxygen gas is reduced, each of the reactant is replaced with the help of other reactant. Therefore, it is a double displacement reaction.
Equation:
C6H12O6 + 6O2 = 6CO2 + 6H2O
Frequently Asked Questions (FAQs)
Question 1: Is there any possibility of displacement reaction when a less reactive metal is made to react with a compound contains more reactive metal?
Answer: A less reactive metal cannot displace a more reactive metal as more reactive metal have tendency to create stable bond with ions. It becomes harder to break that bond for a less reactive metal. Therefore, displacement reaction cannot take place in this kind of reaction.
Question 2: Are Acid-Base reactions considered to be displacement reaction? If yes, then which type of displacement reaction happens in Acid-Base reactions?
Answer: The neutralization reaction between an acid and a base is a great example of displacement reaction. Exchanging the ions with each other to produce neutral salt is the main fact of displacement reaction between acids and bases.
These reactions are double displacement reaction as both the acid and bases replace each other by exchanging the ions.
Question 3: How does displacement reaction depend on reactivity of metals?
Answer: When the more reactive metals are made to react with the compound containing less reactive metals, that more reactive metals show its tendency displace the less reactive metal from the compound and it take the place of that less reactive compound and firms new compound. In this way, displacement reaction depends on the reactivity of metals.
Question 4: What type of displacement reaction can be noticed in photosynthesis?
Answer: Single displacement reaction is noticed to be happening in photosynthesis when glucose is formed by the replacement of oxygen gas from Carbon Dioxide.
Question 5: In which step double displacement reaction can be found to be happened when Vinegar is mixed with baking soda? Which reaction happens in second step?
Answer: In the first step of reaction double displacement takes place. Vinegar contains acetic acid is replaced with the sodium and make sodi8um acetate and the carbonate is replaced into carbonic by getting the hydrogen molecule.
Due to unstable nature of carbonic acid it decomposes and decomposition reaction takes place in the next step.
Covalent double bond was first introduced by Russian chemist, Alexander Butlerov. In this article, “double covalent bond examples” different types of double covalent bond with clear explanations are discussed briefly.
Covalent bond is formed due to sharing of their outer shell electrons between the participating atoms to form the bond. The sharing of electron pairs between two atoms depends upon the electronegativity of the respective atom. It may be single or sigma bond, double or pi bond and triple bond.
Main outlook of the article is double covalent bond. Double covalent bonds are formed due to the overlap of atomic orbitals in lateral orientation. Double bond is containing one sigma and one pi bond. Double bonds are relatively shorter and shorter than single bond. Bond order of double bond is 2. Electron density of double bond is greater and makes the molecule more reactive towards a strong electron acceptor.
In carbon dioxide two double bond is present between carbon with two oxygen and expressed as O=C=O. 2P orbitals of both the carbon and oxygen participate in the bond formation. Head on overlap between two orbitals give sigma bonding and lateral overlap forms pi bond between two atoms. After sharing two electrons from each oxygen for the formation of double bond rest of the four valence electrons of oxygen remain as nonbonded electron pairs.
Double Covalent Bond in Carbon Dioxide. Image Credit: Wikimedia Commons.
Sulfur dioxide
Bonding of sulfur dioxide is similar to the carbon dioxide. Structure and geometry of these two species are different. Carbon dioxide has linear structure whereas sulfur dioxide has angular orientation. Like CO2, in SO2 sulfur has one double bond with each of the oxygen.
Sulfur shares its four valence electrons and oxygen shares its two out of the four valence electrons to form the double bonds. Thus, oxygen has two electron pairs as nonbonded but sulfur has one electron pair as nonbonded electron pairs.
It has also angular structure (<ONO bond angle 1150) like sulfur dioxide. It is written as the resonance structure in which both the nitrogen and oxygen bonds are equivalent. Nitrogen is singly bonded with one oxygen atom and doubly bonded with another oxygen atom. But these two bonds are almost same. Nitrogen uses four out of its five electrons in the covalent bond formation with oxygen and rest of the one electron remain as nonbonded. One of the two oxygen uses two electrons and another one shares none of its valance electron to form the double and single covalent bond with nitrogen respectively.
Resonance Double Bond Structure of Nitrogen Dioxide
Ozone
It is an inorganic gaseous molecule with a bent structure having bond angle 116.80. Central oxygen is attached by one single bond with an oxygen and by one double bond with another oxygen atom. It is also expressed as the resonance structure like nitrogen dioxide (NO2). Central oxygen uses its four electrons to form the covalent bonds and other oxygen atoms use their two electrons and no electrons to form the double bond and single bond with the central oxygen atom respectively.
In ethylene, two carbons are bonded by double bond with each other and four hydrogens are attached by single bond (two in each carbon) with the carbons. All these six atoms (four hydrogen atoms and two carbon atoms) are coplanar and create an angle 117.40. 2px or 2py orbitals from each carbon atom overlap laterally with each other to form the pi bond and sigma bond is formed due to the head on overlap between 2pz orbitals.
Structure of Ethylene
Acetone
Acetone is an organic liquid compound which is high volatile and flammable in nature. In acetone (CH3COCH3), carbonyl carbon atom (not the methyl carbon) is attached with the oxygen atom by double bond. The methyl carbon (CH3) is bonded with the carbonyl carbon by a single covalent bond or sigma bond. Two methyl carbon atoms are also attached with the three hydrogen atoms (in each of the carbon) by sigma bond.
Formaldehyde is the simplest aldehyde and volatile in nature. Like acetone, carbonyl carbon is attached with the oxygen atom by a double covalent bond and two methyl group is substituted by hydrogen atoms in formaldehyde. Two hydrogen is bonded with the carbonyl carbon by one single bond for each of the hydrogen.
Dimethyl sulfoxide is an organosulfur compound widely used as polar aprotic solvent. This colorless liquid can dissolve both the polar and nonpolar substance in it. In its structure sulfur atom is attached with the oxygen atom by double bond and two methyl group is attached with the sulfur atom by single covalent bond known as sigma bond. Methyl carbon atoms are also attached with the three hydrogen groups (in each of the carbon) by single bond.
Diazene, also known as diimide is a compound with molecular formula (NH2)2. It presents as two geometrical isomers (cis and trans). In the structure of diazene, two nitrogen atoms are attached with each other by double covalent bond and attached with the two hydrogen atoms (each hydrogen in each nitrogen) by single sigma bond. One pair of each electron in two nitrogen atoms remain as nonbonded.
Double Covalent Bond in Diazene
Frequently Asked Questions (FAQ)
When covalent bonds are formed?
Answer: Covalent bond is formed between two atoms by sharing of outer shell electron pairs between the two participating atoms. Like the ionic bonds electrons from one atom or molecule are not completely transferred to another atom or molecule.
Why the reactivity of double covalent bond is greater than the single covalent bond?
Answer: Double covalent bonds are relatively more electron rich than the single covalent bonds. Thus, electrophiles attack easily to the molecular species having double bond than single bond.
How many electrons participate in double bond formation?
Answer: A covalent bond is formed by the participation of two electrons. So, four electrons are involved in formation of one double bond.
Why double bonds are shorter than the single covalent bond?
Answer: Bond order of a double bond and a single bond is 2 and 1 respectively. As, bond order is dependent upon the bond strength proportionally and the bond length (by inversely proportional). Thus, double covalent bonds are relatively shorter than the single covalent bond.
This research would provide the fundamental neutralization reaction examples to improve the knowledge about this type of reaction. It is important to know about neutralization reaction as it holds huge impact on regular lifestyle of human being.
The reaction between acid and base and formation of natural salts (pH level around 7) and water is called neutralization reaction. A broad range of Neutralization reaction example has been described through the following topics:
Neutralization reaction happens in strong acid and strong base
In a very basic context it can neutralization stands for the reactions which are reliable in giving out water and salts (neutral compounds). Strong acids and strong bases do not differ from this concept. Two examples of the neutralization reaction between strong acids and strong bases are being discussed below:
Example 1: Simple formation of table salt that is NaCl is the most relevant example of neutralization between strong acid and strong base. The reaction between strong hydrochloric acid and strong sodium hydroxide gives out water and NaCl (Table salt).
Example 2: Another example of divalent acids and bases represents the strength of neutralization reaction. The reaction between Nitric acid (strong acid) and Barium hydroxide (strong base) gives out Barium Nitrate and water.
Equation:
Ba(OH)2 + HNO3 = Ba(NO3)2 + H2O
Neutralization reaction happens in strong acid and weak base
Example 3:Ammonium nitrate salt which is quite stable in nature comes from the neutralization reaction between weak base gaseous ammonia (NH3) and strong nitric acid (HNO3).
Basically, the reaction happens in two stages. At first the ammonia reacts with the proton present in nitric acid and forms and ammonium ion. That ammonium ion then reacts with the produced nitrate ion and gives out the actual ammonium nitrate salt.
Equation:
NH3 + HNO3 = NH4NO3
However, this reaction shows exothermic properties. Ammonium nitrate is highly explosive in nature.
Neutralization reaction happens in weak acid and strong base
Example 4:Carbonic acid (H2CO3) is a well-known weak acid and when it reacts with strong base sodium hydroxide it gives out basic salt of sodium nitrate. Both the acid and base helps each other to get neutralised and produce new stable product.
Though the salt is basic (pH is 11), it is a useful neutral salt anyway.
Other than these the Strontium fluoride also comes from the reaction between highly corrosive Hydrofluoric acid and strong base strontium hydroxide (Sr(OH)2).
Neutralization reaction happens in weak acid and weak base
Example 6:Acetic acid (weak acid) and calcium carbonate (weak base) reacts with each other and forms acetate and water. In this reaction release of CO2 gas is also noticed as exception.
Not exactly exception, it can be noticed that when carbonate bases reacts with acid they give out Carbon Dioxide gases along with water and basic salts.
The cultivation of crops should be carried out in the soil which is neither too basic nor too acidic. For making the soil neutral tis is treated with bases like lime (calcium hydroxide). In the case of reducing acidic nature of the soils organic compounds are mixed with the soils and it does enhance the neutral strength of soils anyway.
As an example magnesium carbonate neutralises the acidic soils and brings forth high-quality nutrients to the plants.
Neutralization reaction examples in pharmaceutical context
Example 8: On the basis of pharmaceutical context it has been identified that the buffer solutions are highly encouraging factors in chemistry. Buffers can be three types’ acidic buffer, basic buffer and neutral buffers.
All the buffers contain acid and bases both and the pH level of buffer solutions are always constant. These solutions re influentially made by using the principle of neutralization reaction. It can be said that these solutions are great example of neutralization reaction product.
Buffer solution as Neutralization reaction examples from Wikimedia
Ammonium acetate is a great example of buffer which is formed by proceeding as neutralization reaction example.
Neutralization reaction in daily life
Example 9: In regular life of human being brushing tooth is the first job for which people do after opening eyes in the morning. The basic toothpaste that has been used by every individual is great and appropriate example of neutralisation.
The acids formed by the food particles inside the gaps between teeth are decayed by the toothpaste (combination of alkaline or basic compounds). It reduces the possibility of tooth decay by keeping the teeth neutralised.
Example 10:The mildly alkaline substance shampoo is used in daily life to wash hairs. The impact of a shampoo on the hair is noticed to follow the neutralization reaction.
Conditioner is used after shampoo to neutralise the mild alkaline effect of shampoo in the hair. It restores the neutralised moist nature in the hair and makes it healthy.
Neutralization reaction in industrial waste treatment
Example 11: the industrial waste formation is very common matter in this recent era. Most of the industrial wastes are acidic and toxic by nature. Therefore, treating those with basic compounds proceeds through neutralization.
It reduces the possibility of damage of nature by the acidic wastes through the proper implementation of neutralization reaction.
Neutralization reaction in Rubber industry
Example 12: In the case of rubber production it is very important to prevent the coagulation of latex. This prevention are noticed to be dine with the application of neutralization reaction where lactic acid are neutralised by the ammonia solution (NH4OH).
Neutralization reaction in human body
Example 13:Antacids are effective example of neutralization reaction. When a person suffers from acidity antacids are recommended to intake. Antacids help to neutralise the acids forms inside the stomach by the basic composition it contains such as magnesium hydroxide or aluminium hydroxide and others.
Neutralization reaction example as Antacids from Wikimedia
Example 14: When bees sing or bite at any body part it the toxicity spreads into human body in the form of formic acid. It is neutralised by the application bases like baking soda or baking powder. It effectively helps to cut off the possibility of inflammation or infection. Basically the base applied proceeds neutralization reaction to reduce toxic effect of the formic acid.
Neutralization reaction takes place as an example of exothermic reaction. It is influenced by the release of extra heat in the nature. Besides neutralization reactions are also the different side of thoughts of double displacement reaction.
Question 1: What is the basic concept of neutralization reaction?
Answer: According to the basic concept of Neutralization reaction, acids and bases react with each other and give out salt and water. The salts appear as stable compound in nature.
Question 2: Does neutralization reaction occur as exothermic reaction? If yes, explain why?
Answer: Yes, Neutralization reactions occur as exothermic reaction. These reactions release a certain heat which is the foremost principle of exothermic reaction.
Question 3: How does Double Displacement reaction take place in neutralization reaction?
Answer: Double Displacement reaction takes place in neutralization reactions when an acid release its cations and the base releases its OH– ions, salt is formed by adopting the cations and water molecules form by adopting OH– ions.
Question 4: Give an example of neutralization reaction where Carbon Dioxide gas appears as product simultaneously with water and salt.
Answer: Acid-carbonate base neutralization reactions produce CO2 along with salt and water, such as,
4HCL + 2Na2CO3 = 4NaCl + 2H2O + 2CO2
Question 5: What is Table salt? How it is formed?
Answer: NaCl is called generally table salt which we put in food in daily life.
It is formed by neutralization reaction between strong acid and strong base
“The equal and opposite forces are applied in two opposite directions results in the detachment of the object.”
This force could be an applied force, gravitational force, drag force, or tensional force. Here is a list of the law of detachment examples that we are going to discuss below:-
Tensional Force in a Rope due to Heavy Load
A tensional force is a force exerted in the rope or string equally and in the opposite direction. Suppose a man is pulling the object with the help of the rope, then the tensional force is created in the rope due to the pulling force by a man in the direction of the object and an equal amount of resistive force is generated from the object in the direction towards man.
If the tensional force in the rope is beyond the resistivity of the rope, then the rope will detach from the point of the center of equivalent force between the two.
Consider an object attached to one end of the rope and another end of the rope is held in the hand of the boy and he is rotating the object in a circular path. The object moving in circular motion experiences a torque on the object that keeps it rotating in a circular motion.
Object in centripetal motion
If the boy suddenly releases the rope from his hand, then the object will detach from his hand and will travel in the direction tangential to the circular path traced by the object.
Leaves shaded from a node of the tree also give an example of detachment law. When the leave gets wither, and the air resistive force is incident on the leaves, the leaves get detached from the nodes and falls down.
Plucking Fruits from the Tree
The force is applied to plug the fruit from the tree. The fruit is attached to the tree from the node.
Fruit detached from the tree; Image Credit: Pixabay
On applying the force to plug the fruit, the equal and opposite for the generated across the node of the tree bearing fruit. This force and the force due to gravity are responsible for the detachment of the fruit from the tree.
The destructive plate means the separation of the two plates apart from each other due to the exertion of the external forces in opposite directions that cause landslides or volcanic eruptions or other destructive activities along the boundary of the plates.
The activities in the asthenosphere are responsible for the migration of the plates floating over it that causes either the construction or destruction of the plate. Well, the destruction of plates is an example that follows the law of detachment.
Exfoliations
Exfoliations are seen in the rocks due to changing weather conditions. During hot days there is a rarefaction between the rock particles as the high intensity radiations cause the removal of water from the rock. While during cold nights, there is a contraction of the molecules in the rocks. Rigorous activities cause the exfoliations in the rock masses thus detaching the mass into groups.
Exfoliation seen in the old boat; Image Credit: Pixabay
Breaking a Glass
Breaking of glass is also an example of detachment, whereupon breaking the pieces of the glass detach from each other.
The force is applied to uproot the tree from the ground. At the same time, the equal and opposite force is exerted by the roots of the tree to keep the tree in place.
Tug of War
The force on the rope during the tug of war is removed when the tension force exerting on the opposite side is high enough to overcome the force exerted on the opposite side. The direction of the force is reversed and the feet of the players detached from the initial position.
The rocks detach from the original rock basin upon erosion and migrate to the other locality on carrying away by external agencies like air, or water flow.
Cutting
Cutting something apart from the matter is also an example of detachment. Upon cutting the part of an object with sharp weapons, the mass of the object gets detached from the remaining part of the mass. The pressure is exerted on the small surface of the object that is responsible for the cleavage to separate apart the object into two parts.
To cut a cello tap using a cutter or by hand, the tensional force is created on pulling the cello tap from both directions. Since it is very delicate, the tensional force exerted on the tap is minute and detaches easily on the application of small force.
Detachment of Handle of Bag
When the weight of the bag is heavier, it becomes difficult to manage the entire load on the tiny handles of the carry bag, because the tensional force supporting the handle is small. In that scenario, the handles of the bag may detach and roll down from the grip.
Unplugging the adapter or charger from the wire is also an example that explains the law of detachment.
Removing the plug from the socket; Image Credit: Pixabay
The force is applied outward to unplug the pin, while the equal force is exerted in the opposite direction within the wall by the socket.
Tearing
There are different types of tear that leads to the detachment caused by the pulling force. The force applied to the object can tear off the object if the density and the potential of the object are less.
Frequently Asked Questions
Is the gravitational force responsible for the detachment of objects?
The gravitational force pulls the object towards the surface of the Earth.
Due to this the object hanging above the surface of the Earth having greater potential energy tends to detach and accelerate down towards the ground if the tensional force holding the object cancels out due to some reason.
Does the elongation of the object lead to detachment?
The elongation of the object is due to the exertion of the force in opposite directions.
The elongation of the force will exert a tensional force across the object. If this force increases then the detachment will occur in the middle of the object.
Elimination reaction is a well known reaction in organic chemistry in which two substituents are removed from one compound followed by either one step or two step mechanism.
E1 reaction (unimolecular elimination reaction) is those type of elimination reaction follows first order kinetics. In rate determining step only one molecular species participate in reaction that is the decomposition step of leaving group from substrate.
E1 reaction proceeds through the following steps-
Ionization step: carbocation is formed after the elimination of leaving group.
Deprotonation step: H+ gets eliminated from another carbon beside the leaving group attached carbon.
Energy Diagram of a Unimolecular Elimination Reaction. Image Credit: Wikimedia Commons
Acid Catalyzed Dehydration of Secondary Hydroxyl Group
This reaction proceeds through E1 pathway. At the very first step hydroxyl group gets protonated in presence of any concentrated acid and form good leaving group (OH2+). This leaving group can be easily eliminated from the substrate forming a stable carbocation. At the final step deprotonation occurs, one H+ atom is eliminated from the carbon beside the carbon attached with leaving group to form the elimination product.
Acid Catalyzed Dehydration of Secondary Hydroxyl Group.
Acid Catalyzed Dehydration of Tertiary Hydroxyl Group
This dehydration process is almost same as the dehydration of secondary hydroxyl group. The difference is that the carbocation generated in this dehydration process is more stable than the previous (30 carbocation is more stable than 20 carbocation). Rest of the mechanism is exactly same.
Dehydrohalogenation of secondary alkyl halide in presence of base like t-butoxide. At the very first stage halide ion (Cl, Br, I) eliminates and secondary carbocation is generated. In the next step, this reaction base eliminates the hydrogen as H+ from the substrate to form the elimination product (alkene). This secondary carbocation is more stable than primary but less stable than tertiary carbocation.
Dehydrohalogenation of secondary Alkyl Halide. Image Credit: Wikimedia Commons
This dehydrohalogenation process follows the same mechanism as the previous example. Halogen is eliminated and a tertiary carbocation is generated in the reaction medium in the rate determining step (slowest step). Basic medium helps to remove the hydrogen ion (H+) from the substrate and two types of alkenes is formed Zaitsev (more substituted alkene) and Hofmann alkene (less substituted alkene).
Dehydrohalogenation of Tertiary Alkyl Halide. Image Credit: Wikimedia Commons
Pyrolysis of aryl sulfonate ester takes place through E1 mechanism. In this example carbocation is generated when the sulfonate ester C-O bond is cleaved. This reaction proceeds at very low temperature. This low temperature helps to produce clean and high yielded desired alkene as the product. The aryl sulfonate that is chosen for this pyrolysis should have only one β hydrogen atom in anti -periplanar configuration with the C-O bond. This reaction proceeds in basic medium to eliminate the hydrogen as H+ ion.
Stereoselectivity and Regioselectivity of E1 Reaction
In E1 reaction generally two types of alkenes are formed. One is more substituted alkene known as Hofmann product and another one is less substituted alkene known as Zaitsev’s product. More substituted product has greater stability with respect to less substituted product. This indicates that the hydrogen comes from most substituted carbon will be deprotonated first than the hydrogen belongs to less substituted carbon.
From the mechanism of E1 reaction it is clear that it is not stereospecific like E2 reaction. For E2 reaction deprotonating hydrogen should be antiperiplanar to the leaving group. But, this criteria may not be followed for E1 reaction.
Kinetic isotope effect is defined as the change of the rate of reaction due to change of one atom by its isotope.
E1 reaction exhibit small primary kinetic isotope effect. When the bond between alpha carbon and hydrogen (Cα-H) is replaced by the heavier isotope of hydrogen (Dueterium) it exhibits secondary kinetic isotope effect and it depends on the stability of carbocation. This isotope effect occurs because the bond strength of C-D bond is almost seven times stronger than C-H bond.
Frequently Asked Questions (FAQ)
Which factor E1 reaction depends on?
Answer: E1 reaction is unimolecular elimination reaction. It depends only on the concentration of substrate because the rate determining step of E1 reaction is the formation of carbocation.
What is an E2 reaction?
Answer: E2 reaction is one type of bimolecular elimination reaction. The rate of an E2 reaction depends on the concentration of substrate as well as the concentration of reagent.
Which substrate is favored for E1 reaction?
Answer: Substrate having tertiary group is favored for E1 reaction because tertiary is most stable carbocation with respect to secondary and primary carbocation due to hyperconjugation effect.
Melting of ice to form water is an example of phase change reaction and it proceeds by endothermic pathway. Ice melts at 273 K or above 273K temperature. For melting of ice at 273K temperature, heat absorbed by system is equal to the latent heat (80cal/g) and for melting ice above 273K temperature heat absorbed by the system is more than this latent heat.
Sublimation of Solid Carbon Dioxide
Sublimation is a phase change process in which solid form is directly changed to vapour state without changing the phase from solid to liquid state. When solid CO2 known as dry ice is sublimed from its solid state to vapour state (gaseous Carbon dioxide), the system absorbs a large amount of heat from surroundings. Thus sublimation of solid CO2 is an example of endothermic process.
Calcium carbonate can be prepared by the reaction between calcium hydroxide and carbon dioxide.
Ca(OH)2 + CO2→ CaCO3 + H2O
When calcium carbonate is decomposed in presence of heat it produces calcium oxide (CaO) and CO2.
CaCO3 → CaO + CO2
Photosynthesis
Photosynthesis, an endothermic reaction, proceeds by absorbing sunlight (light energy). During photosynthesis, chlorophyll absorbs sunlight and carbon dioxide is reduced in presence of water to form glucose molecule.
Evaporation of water needs energy in form of heat to form vapour. Phase change (liq=vap) takes place through the evaporation of water. Evaporation of water takes place at 373K or above 373K. When water evaporated at 373K (1000C) the energy absorbed is equal to latent heat of evaporation (540cal/g) and for above 373K heat will be absorbed more than this latent heat of evaporation.
Partial Oxidation of Natural Gas
Partial oxidation of natural gas is definitely an endothermic reaction at it takes place under a very high temperature (1200-15000C). Natural gas contains methane (CH4) and it undergoes oxidation in presence of steam (H2O). Hydrogen and carbon monoxide gas are obtained as the product of this partial oxidation process.
CH4 (g) + H2O (g)→ CO (g) + 3H2
Formation of Nitric Oxide
In formation of nitric oxide heat energy is absorbed and thus del H is positive for this reaction. Almost 181 KJ amount of energy is absorbed during this reaction when dinitrogen and dioxygen reacts with each other.
N2 + O2→ 2NO
Dissolving Ammonium Chloride in Water
Ammonium chloride (NH4Cl), a solid crystalline compound, is a product of ammonia and chlorine. In water it is dissociated into its two constituent atoms, ammonium cation (NH4) and chloride anion (Cl–).
NH4Cl (s)→ NH4+ (aq) + Cl– (aq)
NH4+ (aq) + H2O (liq) → NH3 (aq) + H3O+ (aq)
H3O+ + OH–⇌ 2H2O (reversible reaction)
This dissolution proceeds towards forward direction by absorbing heat. Thus enthalpy change will be always positive.
Ion pairs are formed mainly in solution due to electrostatic attraction force between positively and negatively charged ions. Formation of ion pairs proceeds through releasing of energy (exothermic process). Separation of ion pair occurs when this distinct chemical entity containing two positively charged ions gets separated and form two ions. Absorbing thermal energy is the main determining factor to proceed in the forward direction. So, it is the reverse process of formation of ion pair, and it is an endothermic process.
Melting of Solid Salts
Salt is one type of crystalline compound having very high melting point. But this solid salt is melted at standard temperature and pressure. Regular table salt (NaCl) has a melting point 8000C and heat of fusion (ΔH(fusion)) is 520 Joule per gram. Melting of solid salt requires high thermal energy and high positive enthalpy change.
Reaction of Thionyl Chloride with Cobalt (II)
Reaction between cobalt chloride hexahydrate with thionyl chloride give hydrochloric acid, cobalt chloride and sulfur dioxide as products. This is an endothermic process and takes place by absorbing heat from the surroundings. Temperature of the reaction medium is decreased from 160C to 5.90C and change of enthalpy is positive.
CoCl2. 6H2O + 6SOCl2→ CoCl2 + 12HCl + 6SO2
Formation of a Cation in Gas Phase
Formation process of cation in gas phase requires thermal energy. To form a cation, energy equals to ionisation energy is needed to remove electrons from valence shell of an atom.
This ionisation energy depends on the electronic configuration of the respective atom. Thus formation of cation is definitely an endothermic process. Whereas formation of anion is an example of exothermic process because after adding electron on valence shell, some energy will be released.
Some numerical problems with answers on endothermic process is discussed below-
Calculate del H for the process-N2 (g) +2O2 (g) = 2NO2 (g)The enthalpy change for the given reactions are-
Resultant equation will be = N2 (g) + 2O2 (g) → 2NO2 (g) Thus, enthalpy change of this reaction is = {180.5 +2×(-57.06)} KJ = 66.38 KJ.
This is an endothermic reaction as the change of enthalpy is positive.
Calculate the change of enthalpy for the following reaction : Hg2Cl2 (s) = 2Hg (l) + Cl2 (g)Enthalpy change for the given reactions are – Hg (liq) + Cl2 (g) = HgCl2 (s) ΔH= -224KJHg (liq) + HgCl2 (s) = Hg2Cl2 (s) ΔH = -41.2 KJ
Answer: The above given reactions can be written as-
Resultant equation will be: Hg2Cl2 (s) = 2Hg (l) + Cl2 (g)
Thus, change of enthalpy is = (224 + 41.2) KJ = 265.2 KJ.
Calculate the change of enthalpy for the following reaction – CO2 (g) + H2O (liq) = CH4 (g) + O2 (g)Given enthalpy change for CH4, H2O and CO2 are -74.8, -285.8 and -393.5 KJ/mol respectively.
Answer: change of enthalpy = enthalpy of products – enthalpy of reactants.
How can the rate of an endothermic reaction be increased?
Answer: An endothermic reaction depends on temperature of reaction medium. Decreasing the temperature of reaction medium increases the extent of reaction towards forward direction.
What is the change of entropy for an endothermic reaction?
Answer: Change of entropy for an endothermic reaction is always negative an energy is absorbed from surroundings to system
State a reaction which will always be an endothermic reaction?
In this article, “exothermic reaction examples”, different types of examples and some numerical problems with solutions on exothermic reaction are discussed briefly.
Exothermic reaction is defined in thermodynamics as one type of reaction in which energy is released in form of heat (sometimes in form of light, sound or electricity) from system to surroundings.
For an exothermic reaction change of enthalpy (ΔH) is negative (less than zero).
Energy Diagram of an Exothermic Reaction. Image Credit: Wikimedia Commons
Combustion reaction is a well known example of high temperature exothermic reaction. Combustion is basically a redox chemical reaction in which any compound is getting oxidized in presence of atmospheric oxygen and most of the times oxidized gaseous products are obtained.
Balanced equation of methane combustion is written below-
CH4 + 2O2 = CO2 + 2H2O
Neutralization Reaction
Neutralization reaction is one type of reaction in which acid gets neutralized by adding base in dropwise manner. So, this is one type of titration. After neutralization, no excess H+ or OH– ion remain unreacted in reaction medium.
Corrosion is one type of oxidation reaction in which a gas containing oxygen (air) attacks at the surface of a metal to form an oxide.
Rusting of iron is one type of corrosion reaction because during rusting iron metal is oxidized by atmospheric oxygen in normal temperature in presence of moisture.
4Fe + 3O2 +2xH2O = 2Fe2O3.xH2O
Crystallization of Sodium Acetate or “Hot Ice”
Solid sodium acetate trihydrate is heater above 330 K and the three crystal water molecules get eliminated and the anhydrous crystal is dissolved in water. The crystal is completely dissolved at 352K. The heat of hydration of sodium acetate trihydrate (ΔHhyd) is above 40 kcal/mol, an endothermic process. Thus, the reverse process, crystallization is an exothermic process.
Making of an Ice Cube
Formation of ice from water is an example of phase change reaction. During this phase change some amount of energy in form of heat is released to surroundings. Water freezes below 273K and loses some amount of energy in form of heat to surroundings to form ice. If water at 273K freezes and form ice at the same temperature then the amount of energy is released is equal to the latent heat (80cal/g).
Nuclear fission generates a large amount of energy as in nuclear fission mass is converted into energy according this law ΔE= Δm×c2. In the fission reaction is splitting of any atom’s nucleus into two small constituent atoms by attacking a neutron(0n1). It is also an example of chain reaction as in every step of nuclear fission neutron is generated and this newly generating neutron can attack another uranium nucleus.
Aerobic and anaerobic respiration occurs in mitochondria in a cell and generates heat energy to help in different biological activities in living organism. So, in the list of exothermic reaction example respiration must be included. 38 ATP and 2 ATP releases per glucose molecule for aerobic and anaerobic respiration respectively. For aerobic respiration, almost 3000 KJ/mol energy is released when glucose (food stuff) is oxidized by oxygen.
C6H12O6 + 6O2 = 6CO2 + 6H2O+ Energy
Formation of Ion Pairs
Formation of ion pairs or ion association is defined as when two ions having opposite electrical charge come in contact with each other in a solution and form a distinct chemical entity. This positive and negative charged two ions comes in contact due to electrostatic force of attraction between them. In formation of this distinct ionic entity an amount of energy release and ΔH becomes negative.
Reaction of ferrous oxide with aluminum is called thermite reaction and the mixture of these two compounds is known as thermite. These two reactants must be in powder form. This reaction generally releases a large amount of energy with aluminum oxide, elemental iron and light.
Fe2O3 + 2Al = 2Fe + Al2O3
Decomposition of Vegetables into Compost
This decomposition is carried out by microbes and requires greater amount of energy for breaking the chemical bonds present in those vegetables. This reaction also proceeds through exothermic pathway.
Solution of Sulfuric Acid and Water
Sulfuric acid reacts with water instantly and it is a high exothermic reaction. That is why water is not poured in the beaker concentrated sulfuric acid, rather sulfuric acid is added slowly in water. After adding water into acid it will start boiling and temperature reaches in a very high value within a short time.
Different numerical problems on exothermic reaction are discussed below-
1.Consider the reaction of water formation. 2H2 (g) + O2 (g) = 2H2O (g). The bond dissociation energy of H-H bond O=O bond and O-H bond are 105 kcal/mol and 119 kcal/mol 110 kcal/mol respectively. Calculate the amount of energy absorbed and released and state it as exothermic or endothermic reaction.
Answer: The balanced equation of water formation is-
2H2 (g) + O2 (g) = 2H2O (g).
In reactant side total energy possessed by reactants =2 (H-H bond) + 1 (O=O bond) = {(2 ×105) + 119} kcal/mol = 329 kcal/mol
In product side total energy possessed by water molecule = 4(O-H bond)
Thus it is an exothermic reaction (enthalpy change negative).
2. Calculate the released energy in the following nuclear fission reaction- 238U = 95Sr + 140 Xe + 3n.
The atomic mass of 238U= 238.050784 amu, 95Sr = 94.919388 amu, 140Xe = 139.921610 amu and mass of neutron (0n1) = 1.008665 amu.
Answer: Mass of the products = {94.919388 + 139.921610 + (3×1.008665)} amu = 237.866993 amu. Mass of the reactant = 238.050784 amu Mass defect = (238.050784 – 237.866993) amu = 0.183791 amu. Energy released due to mass defect = Δm×c2 = 171.20 MeV.
3.Calculate del H for the reaction- 2NO2 (g) = N2 (g) + 2O2 (g)
The enthalpy changes for the reaction given below-
Resultant equation will be = 2NO2 (g) = N2 (g) + 2O2 (g) Thus, enthalpy change of this reaction is (ΔH) = {-180.5 + (2×57.06)} KJ = -66.38 KJ.
Frequently Asked Questions (FAQ)
How can the rate of an exothermic reaction be increased?
Answer: Exothermic or endothermic reaction depends on temperature. If temperature of the reaction medium is increased then the extent of exothermic reaction will be increased.
What is the difference between an exothermic and an endothermic reaction?
Endothermic Reaction
Exothermic Reaction
Endothermic reaction absorbs energy
Exothermic reaction releases energy.
Change of enthalpy (ΔH) is positive.
Change of enthalpy (ΔH) is negative.
Decreasing of temperature increases the rate of the reaction
Increasing of temperature favors the forward reaction.
What is the change of entropy for an exothermic reaction?
Answer: For an exothermic reaction entropy of surroundings always increases as energy is released from system to surroundings.
