Carbon & Its Compounds

 

Carbon

-> The name of the carbon is derived from latin word “Carbo”  which 

means Coal.

-> It is a non-metal.

-> Most of the carbon is poor conductor of electricity & heat.

-> The earth crust has mainly 0.02% of carbon present in the form

 

of minerals such as carbonates, coal, hydrogen carbonates.

-> The atmosphere has 0.03 % of carbon in the form of CO₂.

-> Isotopes of carbons are ₆C¹², ₆C¹³ and ₆C¹⁴.

Note

* Carbon is a very special element because of the following 

reasons:-

(i) Carbon form covalent bond.

(ii) It has 4 electrons in valence shell.

(iii) It has an ability called “Catenation” i.e. self combination, which is used to 

form a long chain of carbon.

(iv) It is tetravalent in nature

* Most of the carbon is poor conductor of electricity because they form covalent 

bond and it also doesn’t dissociate into ions when dissolve in aqueous solution.

As a result, no flow of charge between the particles of carbon,  that’s 

why carbon is known as poor conductor of electricity.

* Most of the carbon is poor conductor of heat because atoms of carbon do not 

have free electrons in the conduction band. 

   

       Therefore they do not conduct well at room temperature, that’s 

why carbon is known as poor conductor of heat.

If the temperature is increased, more electrons acquire energy and start 

contributing to conduction.

-> Conduction band- It is a delocalized band of energy levels in a crystalline

 

solid which is partly filled with electrons.

Bond

-> This is a force of attraction which combines two or more atoms or 

molecules together.

Three types of bonds are:-

(i) Covalent bond

(ii) Ionic bond 

(iii) Coordinate bond

* Covalent bond- A bond which is formed by mutual sharing 

of electrons between two atoms or molecules. This type of bond 

is called covalent bond.

It is also called molecular bond.

e.g. H-Cl, Cl-Cl

Types of covalent bond

* Polar covalent bond

* Non-polar covalent bond

(i) Polar covalent bond- When covalent bond is formed between two 

atoms of different electronegativity then shared electrons attracted 

towards more electronegative atom. This type of bond is called polar 

covalent bond.

           In other words, in polar covalent bond a pair of electrons is 

unequally shared between two atoms.

e.g. H-Cl

(ii) Non-Polar covalent bond- When covalent bond is formed between 

two atoms of same electronegativity then such covalent bond is called 

non- polar covalent bond.

      In other words, In Non-polar covalent bond a pair of electrons 

is equally shared between two atoms.

e.g. Cl-Cl, O=O

Note- A pair of electrons that is shared between two atoms is called 

a bond pair. 

and

A pair of electrons that isn’t shared between two atoms is called 

a lone pair.

* Ionic bond- An ionic bond is formed when a metal atom transfer one or 

more electrons to a non metal atom.

As a result the metal become positive charge atom and non-metal atom 

becomes a negative charge atom.

It is also called electrovalent bond.

e.g. MgCl₂, CaCl₂, MgO, Na₂S, NaCl, etc.

Note- Positively charged ions gets attracted by the non-metal through 

electrostatic force of attraction acting between metal and non-metal.

            Na -----> Na⁺ + e^-

          

            Cl + e^- ------> Cl^-

* Coordinate bond- It is a type of bond which is formed due to share a 

pair of electron by a single atom.

In other words, both electrons come from the same atom in Coordinate 

bond.

      It is also called a dative covalent bond.

e.g. So₂^2-, NH₄⁺, H₃0⁺, etc.