Question

The O–H stretching vibration of alcohols absorbs in the region 3700–3500 cm\(^{-1}\). The O–H stretching of carboxylic acids absorbs in the region:

• A. 3090–3700 cm\(^{-1}\)
• B. 3000–2500 cm\(^{-1}\)
• C. 3700–3500 cm\(^{-1}\)
• D. 1700–2000 cm\(^{-1}\)

Hint:

Carboxylic acids exhibit a broad O–H stretch around 3000–2500 cm\(^{-1}\) due to hydrogen bonding.

Answer 1

The Correct Option is B

Step 1: IR absorption regions. The O–H stretch in alcohols absorbs around 3700–3500 cm\(^{-1}\). The O–H stretch in carboxylic acids absorbs in the 3000–2500 cm\(^{-1}\) range due to hydrogen bonding.
Step 2: Conclusion. Thus, carboxylic acids absorb O–H stretch in the range 3000–2500 cm\(^{-1}\).