Question

What is the measurement of C-O-C bond angle in methoxymethane?

• A. 108$\degree$
• B. 111.7$\degree$
• C. 90$\degree$
• D. 60$\degree$

Answer 1

The Correct Option is B

The measurement of the C-O-C bond angle in methoxymethane (also known as dimethyl ether) is crucial to understanding its molecular geometry. Methoxymethane is an ether where the two methyl groups are bonded to an oxygen atom via single bonds, forming a C-O-C linkage. The oxygen in ethers is sp³-hybridized, which typically suggests a tetrahedral geometry around the oxygen atom. 

In a perfect tetrahedral geometry, the bond angle would be 109.5°. However, in the case of methoxymethane, the C-O-C bond angle is slightly larger. This expansion is due to the lone pair-bond pair repulsion being greater than bond pair-bond pair repulsion, leading to a bond angle of approximately 111.7°.

The options provided are:

• 108°
• 111.7°
• 90°
• 60°

Among these, the correct C-O-C bond angle in methoxymethane is 111.7°.

Answer 2

The C-O-C bond angle in methoxymethane (also known as dimethyl ether) is approximately 111.7°. This bond angle is observed between the oxygen atom and the two methyl groups (CH₃) attached to it in the ether functional group (–O–).

The bond angle in methoxymethane is influenced by the sp³ hybridization of the oxygen atom. In an idealized tetrahedral structure, the bond angle would be 109.5°, but due to the lone pairs of electrons on the oxygen atom, the angle is slightly compressed, resulting in a bond angle of around 111.7°. The electron pairs on oxygen exert a repulsive force that slightly increases the bond angle between the methyl groups.

This bond angle is characteristic of ethers, where oxygen is the central atom, and it differs from the bond angles in alcohols (around 104.5°), where the oxygen is also sp³ hybridized but the geometry is influenced by hydrogen bonding.