What two strong absorptions are characteristic of the IR spectrum of carboxylic acids? A)A C=O absorption at 1710 cm^-1 and a C-H absorption at 3000 cm^-1. B)A C=O absorption at 1710 cm^-1 and an O-H absorption at 2500-3500 cm^-1. C)A C=O absorption at 1600 cm^-1 and an O-H absorption at 2500-3000 cm^-1. D)A C-O absorption at 1500 cm^-1 and an O-H absorption at 2500-3500 cm^-1.

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Quizplus · Accepted Answer

Carboxylic acids have a characteristic C=O absorption at around 1710 cm-1, but they also have a broad and strong O-H absorption due to hydrogen bonding at around 2500-3500 cm-1. This makes option B the best choice. Option A is incorrect because carboxylic acids do not typically have C-H bonds. Option C is incorrect because the C=O absorption for carboxylic acids is typically higher in frequency at around 1710 cm-1. Option D is incorrect because carboxylic acids do not typically have a C-O absorption.

What Two Strong Absorptions Are Characteristic of the IR Spectrum