Class 10 Chemistry

Carbon and Its Compounds

Carbon: Introduction

Atomic Number: 6
Electronic configuration: 2, 4
Valence electrons: 4
Property: Non-metal

Abundance: Carbon is the 4th most abundant substance in universe and 15th most abundant substance in the earth’s crust.

Compounds having carbon atoms among the components are known as carbon compounds. Previously, carbon compounds could only be obtained from a living source; hence they are also known as organic compounds.



Bonding In Carbon: Covalent Bond

Bond formed by sharing of electrons is called covalent bond. Two of more atoms share electrons to make their configuration stable. In this type of bond, all the atoms have similar rights over shared electrons. Compounds which are formed because of covalent bond are called COVALNET COMPOUNDS.

Covalent bonds are of three types: Single, double and triple covalent bond.

Single Covalent Bond: Single covalent bond is formed because of sharing of two electrons, one from each of the two atoms.

Formation of hydrogen molecule (H2)

Atomic Number of H = 1
Electronic configuration of H = 1
Valence electron of H = 1

Hydrogen forms a duet, to obtain stable configuration. This configuration is similar to helium (a noble gas).

Since, hydrogen has one electron in its valence shell, so it requires one more electron to form a duet. So, in the formation of hydrogen molecule; one electron from each of the hydrogen atoms is shared.

bond formation hydrogen molecule

Formation of hydrogen chloride (HCl):

Valence electron of hydrogen = 1
Atomic number of chlorine = 17
Electronic configuration of chlorine: 2, 8, 7
Electrons in outermost orbit = 7
Valence electron = 7

bond formation hydrochloric acid

Formation of chlorine molecule (Cl2):

Valence electron of chlorine = 7

bond formation chlorine molecule

Formation of water (H2O)

Valence electron of hydrogen = 1
Atomic number of oxygen = 8
Electronic configuration of oxygen = 2, 6
Valence electron = 6

bond formation water molecule

Oxygen in water molecule completes stable configuration by the sharing one electron from each of the two hydrogen atoms.

Formation of Methane (CH4)

Valence electron of carbon = 4
Valence electron of hydrogen = 1

bond formation methane

Formation of Ethane (C2H6):

bond formation ethane


Double covalent bond: Double bond is formed by sharing of four electrons, two from each of the two atoms.

Formation of oxygen molecule (O2):

Valence electron of oxygen = 2

bond formation oxygen molecule

In the formation of oxygen molecule, two electrons are shared by each of the two oxygen atoms to complete their stable configuration.

In oxygen, the total number of shared electrons is four, two from each of the oxygen atoms. So a double covalent bond is formed.

Formation of Carbon dioxide (CO2):

Valence electron of carbon = 4
Valence electron of oxygen = 6

bond formation carbon dioxide molecule

In carbon dioxide two double covalent bonds are formed.

Formation of Ethylene (C2H4):

Valence electron of carbon = 4
Valence electron of hydrogen = 1

bond formation ethylene

Triple Covalent Bond: Triple covalent bond is formed because of the sharing of six electrons, three from each of the two atoms.

Formation of Nitrogen (N2):

Atomic number of nitrogen = 7
Electronic configuration of nitrogen = 2, 5
Valence electron = 5

bond formation nitrogen molecule

In the formation of nitrogen, three electrons are shared by each of the nitrogen atoms. Thus one triple bond is formed because of the sharing of total six electrons.

Formation of Acetylene (C2H2):

bond formation acetylene

Properties of Covalent Bond:

  • Intermolecular force is smaller.
  • Covalent bonds are weaker than ionic bond. As a result, covalent compounds have low melting and boiling points.
  • Covalent compounds are poor conductor of electricity as no charged particles are formed in covalent bond.
  • Since, carbon compounds are formed by the formation of covalent bond, so carbon compounds generally have low melting and boiling points and are poor conductor of electricity.

Next

Alkane

Alkene Alkyne

Nomenclature

Nomenclature 2

Chemical Properties

NCERT Solution

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