Question

The C-O-C bond angle in ethers is _______

(a) lesser than 109.5°

(b) 109.5°

(c) greater than 109.5°

(d) 180°

This question was addressed to me by my school principal while I was bunking the class.

My question is taken from Structures of Functional Groups in portion Alcohols, Phenols and Ethers of Chemistry – Class 12

Answer 1

Correct answer is (c) greater than 109.5°

To elaborate: Due to the repulsive interaction of the bulky alkyl/aryl groups in ethers, the bond angle is slightly more than the tetrahedral angle, i.e., 109.5°. For example, the C-O-C bond angle in methoxymethane is 111.7°.