1. Which of the following statements is true about the

hybridization of carbon atoms in ethane, ethene and

ethyne?

a) Ethane has sp hybridization, ethene has sp2

hybridization and ethyne has sp3 hybridization.

b) Ethane has sp3 hybridization, ethene has sp2

hybridization and ethyne has sp hybridization.*

c) Ethane has sp2 hybridization, ethene has sp

hybridization and ethyne has sp3 hybridization.

d) Ethane has sp3 hybridization, ethene has sp

hybridization and ethyne has sp2 hybridization.

Rationale: The number of hybrid orbitals formed by carbon

is equal to the number of sigma bonds and lone pairs

around it. Ethane has four sigma bonds, ethene has three

sigma bonds and one pi bond, and ethyne has two sigma

bonds and two pi bonds. Therefore, ethane has sp3

hybridization, ethene has sp2 hybridization and ethyne has

sp hybridization.

2. Which of the following compounds is an example of a

carboxylic acid?

a) CH3CH2OH

b) CH3COOH*

c) CH3CHO

d) CH3NH2

Rationale: A carboxylic acid is a compound that contains a

carboxyl group, which is -COOH. CH3COOH is the

simplest carboxylic acid, also known as acetic acid or

vinegar. The other compounds are alcohols, aldehydes and