In this, article we are going to study examples of various covalent bond types of atoms.
A covalent bond is usually formed between the atoms that belong to non- metallic elements. Do a covalent bond should necessarily have a difference in their electronegativities. So in order to understand properties and facts related to this we will study covalent bond types of atoms in detail.
H2O atoms example of covalent bond types of atoms
As we can see in the structure of a water molecule it contains one hydrogen atom and two hydrogen atoms which form a covalent bond. The covalent bonding of these atoms can be explained by the lewis dot structure concept.
We know that the oxygen atom has 6 valence electrons and hydrogen has one valence electron (since there are two hydrogen atoms, the total hydrogen valence electrons will be 1×2=2 electrons). The total valence electrons will be 6+2=8 electrons. One electron pair is shared between each of the two hydrogen atoms and the oxygen atom and in this way, the valency of both atoms is satisfied by forming a covalent bond. H2O is an inorganic compound which has polarity. This particular compound is colorless and does not have any odor. Also, H2O is the only compound which can exist in 3 forms (solid, liquid, and gas).
Talking about its magnetism it is diamagnetic in nature. It’s freezing point is zero degrees Celsius and boils at a temperature of 100 degrees Celsius. Due to polar nature, it can exhibit hydrogen bonding. Taking into account the reactivity of H2O molecule, elements ( metallic, usually the alkali and alkaline earth metals e.g. sodium, potassium, calcium, Lithium, etc.) which are seen to be more electropositive in comparison to hydrogen have the ability to displace hydrogen in H2O molecule. And they for. Hydroxides and release hydrogen. At higher temperatures, carbon is seen to react with steam and form hydrogen and carbon monoxide.
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C2H5OH (ethanol) atoms
The structure of ethanol has two carbon atoms, 6 hydrogen atoms, and one oxygen atom which form a covalent bond. The covalent bonding these atoms can be explained by the lewis dot structure concept.
We know that a carbon atom has 4 valence electrons (since there are two carbon atoms, the total carbon valence electrons will be 4×2=8 electrons) and hydrogen has one valence electron (since there are six hydrogen atoms, the total hydrogen valence electrons will be 1×6=6 electrons). The valence electrons in oxygen atom are 6.The total valence electrons will be 8+6+6=20 electrons. One carbon atom shares one electron pair each with three hydrogen atoms and forms bond with the second carbon by sharing one pair of electrons, thus satisfying its valency.
The second carbon atom shares one pair of electrons each with two hydrogen atoms and forms single bond with neighboring oxygen by sharing one pair of electrons. In this way the second carbon satisfies its octet. The oxygen forms one bond with hydrogen by sharing one pair of electrons and obtains a complete octet. It’s synonym is ethyl alcohol and it is an organic compound which is volatile in nature. In appearance it is a liquid (colorless) and has odor somewhat like wine.
It’s density is around 0.789 g/cm3 ( at a temperature of around 20 degrees Celsius). Its melting point is said to be -114 degrees Celsius and boils at a temperature of 78 degrees Celsius. The refractive index of ethanol is more than water i.e. 1.361. It is seen to be miscible with various organic compounds like pyridine, carbon tetrachloride, chloroform, acetone, toluene etc. including water.
O3 (ozone) atoms
The structure has 3 oxygen atoms which are associated by covalent bonding. The valence electrons in oxygen atom are 6 and since there are 3 oxygen atoms, the total oxygen valence electrons will be 6×3=18 electrons.
The central oxygen atom shares one electron pair with one oxygen forming a single bond and shares two electron pair with one more oxygen forming double bond. In this way the valency of all the three oxygen atoms is satisfied. It’s synonym is trioxygen and it is an inorganic compound. In appearance it pale blue color gas. It’s density is around 2.144 mg cm-3 at a temperature of zero degrees Celsius. Its observed melting point is -192 degrees Celsius and boils at a temperature of -112 degrees Celsius.
Talking about its solubility it soluble (slightly) in water but is more soluble in inert type (non polar) solvents like that of carbon tetrachloride. It is considered to be a very powerful oxidizing agent and much more powerful in comparison to oxygen. It is not stable at higher concentrations and hence seen to decay to oxygen (diatomic). We know that how important is ozone to us, as it protects earth from harmful uv radiations.
Cl2 (chloride) atoms
The structure has two chlorine atoms in the structure which form covalent bond. The covalent bonding can be explained by using lewis dot structure concept.
The valence electrons in chlorine atom is 7, since there are 2 atoms of chlorine the total chlorine valence electrons will be 7×2=14 electrons. One electron pair is shared between two chlorine atoms and this way the valency of both the chlorine atoms is satisfied. Usually chlorine exists in the form of gas. Its observed melting point is -101.5 degrees Celsius and boils at a temperature It has been observed to boil at a temperature of around -34.04 degrees Celsius. Its density is 3.2 g/L. The oxidation states exhibited by chlorine are -1, +1, +2, +4, +6 and so on.
There are two stable isotopes of chlorine which are produced in the process of oxygen and silicon burning process. Chlorine being very reactive does not occur as free element instead it occurs as salts of chloride. It has been observed that chlorine gas is quite toxic and can be very hazardous to skin and eyes. Being very powerful oxidizer it has the capability to react with materials that are flammable. Coming to some applications of chlorine, it is used in disinfecting process of water and is also an active component in water treatment at sewage and industrial levels.
O2 (oxygen) atoms
The structure of oxygen has two atoms of oxygen which are associated by covalent bonding. We can explain bonding in the molecule by lewis dot structure concept.
The valence electrons in oxygen atom is 6 and since there two atoms of oxygen the total valence electrons will be 2×6=12 electrons. Two electron pairs are shared between the two oxygen atoms forming a double bond and hence satisfying each others valency. Oxygen belongs to group of chalcogens (in the periodic table), though it is a non metal it is very reactive and acts as a powerful oxidizing agent. In appearance it exists as a pale blue color gas and sometimes liquid and solid as well.
It’s observed melting point is -218 degrees Celsius and boils at a temperature of -182 degrees Celsius. Its density is 1.429 g/L. The oxidation states exhibited by it include -2, -1, 0, +1, +2. It gas a cubic crystal structure and is is paramagnetic in nature. It dissolves in water and also more in fresh water rather then seawater. Oxygen is exists in abundance on the earth’s surface. Coming to its applications, can we even imagine a life without oxygen? No its very important to human life.
N2 (Nitrogen) atoms
In the structure There are 2 nitrogen atoms that bond by covalent bond. Here as well we can use lewis dot structure to explain covalent bonding in nitrogen.
The valence electrons most of the times are 3. Since there are 2 nitrogen atoms the total valence electrons in Nitrogen include 2×3=6 electrons. Three electron pairs are shared between the two nitrogen atoms forming a triple bond between them. In appearance it is a gas (colorless) and sometimes exists as liquid and solid as well. The oxidation states exhibited by it includes-3, -2, -1, 0, +1, +3 which form quite acidic oxides. It exhibits hexagonal crystal structure.
Nitrogen is a very important compound as it is used to prepare many important chemicals in the industries( e.g. ammonia). There exists two stable isotopes of nitrogen. Talking about the production of nitrogen it is produced by the process of fractional distillation of the liquid air. Taking account the applications of nitrogen ot is used in making of explosives, dyes, Nylon.
HCl (hydrochloric acid) atoms
The structure has one hydrogen atom and one chlorine atom which are associated by covalent bond. We can explain bonding here by lewis dot structure concept.
The valence electrons in hydrogen atom is and in chlorine is 7. So total valence electrons in molecule will be 1+7=8 electrons. Any of the seven electrons are utilized to form bond with hydrogen. So one electron pair is shared between the hydrogen and chlorine atom and thus forming a single bond. In appearance it exists as a colorless liquid and has somewhat pungent kind of odor.
The parameters like melting point, boiling point, density, pH depends on concentration of hydrochloric acid. Coming to the applications of HCl it is used as pickling agent in steel for removing rust from it. In solutions it is used as a pH controlling agent. It is used a regenerating agent in ion exchange resins. Also it is a very important reagent in a laboratory.
H2 (hydrogen) atom
In the structure there are two atoms of hydrogen which are bonded by covalent bonding. The valence electrons in hydrogen is one and since there are two hydrogen atoms the total valence electrons will be two.
One electron pair will be shared between the two hydrogen atoms, thus satisfying valency of both the atoms. The resultant bond is a single bond. It exhibits a hexagonal crystal structure and the oxidation states that it exhibits include -1 and +1. The energy of the electrons at ground state energy level is around -13.6 eV.
Hydrogen is seen to be not much reactive at standard conditions but can form compounds with various elements also it is soluble in various rare earth metals and transition metals.
CO2 (carbon dioxide) atoms
In the structure There are two oxygen atoms and one carbon atom which are bonded covalently.
The valence electrons in the oxygen atom are 6 (since there are two oxygen atoms, the total valence electrons of oxygen are 2×6=12 electrons )and in carbon atom 4. The total valence electrons in the molecule will be 16 electrons. Two electron pairs are shared between the central carbon and each of the two oxygen atoms which are present at the side. The resultant bond formed will be double bond.
In this way the valency of all the atoms is satisfied. In appearance it is a gas (colorless). Its observed density is around 1.977 kg/m3 at a temperature of around zero degrees Celsius. It is seen to be soluble in H2O. Talking about its odor it does not have any odor at lower temperatures but at higher temperatures it exhibits acidic kind of odor.
1)Which of the above gas is used as fuel in rockets ?
Ans Hydrogen is used as fuel in rockets. And nowadays green hydrogen is trending as it does not pollute the environment.
2)Which of the above compounds the parameters like melting point, boiling point, density, pH depend on concentration ?
Ans Hydrochloric acid