Question

What is the value of C-O-H bond angle in CH\(_3\)-OH?

• A. 108.9°
• B. 107°
• C. 109.5°
• D. 110°

Hint:

In molecules like CH\(_3\)-OH, the bond angles are slightly less than the ideal tetrahedral angle due to the presence of lone pairs on the oxygen atom.

Answer 1

The Correct Option is A

Step 1: Understanding the structure of CH\(_3\)-OH.
In methanol (CH\(_3\)-OH), the carbon is sp\(^3\) hybridized, and the bond angle around the oxygen atom is slightly less than the ideal tetrahedral angle (109.5°) due to lone pair-bond pair repulsion. The actual bond angle is around 108.9°.

Step 2: Analyzing the options.
(A) 108.9°: This is the correct bond angle, as it accounts for the lone pair-bond pair repulsion.
(B) 107°: This is too low and is not the correct value.
(C) 109.5°: This is the ideal bond angle for a perfect tetrahedral geometry, which is not the case here due to the lone pair.
(D) 110°: This is slightly too high for the bond angle in CH\(_3\)-OH.

Step 3: Conclusion.
The correct bond angle is 108.9°.