Question

Q.1) Explain the nature of C-X bond based on following points:) C- X bond enthalpy

Answer 1

The nature of C-X bond, based on C-X bond enthalpy, follows the given order of strength :

C-F > C-Cl > C-Br > C-I

• Bond enthalpy is defined as the amount of energy involved in breaking a bond.

• A C-X bond is a polar covalent between a carbon atom and a halogen atom, such as F, Cl, Br, or I.

• Now, F is the halogen with the smallest size, followed by Cl, then by Br, and I being the largest in size.

• As the size of the halogen atom increases, the bond length between the carbon and the halogen increases.

• With an increasing distance, the force of attraction between the polar atoms decreases and consequently, lesser enthalpy is required to break the bond.

• Therefore, the C-X bond strength on the basis of their enthalpy follows the order :

C-F > C-Cl > C-Br > C-I;

C-F being the strongest and C-I being the weakest bond.