A strong signal at 3400 cm^–1 in an IR spectrum indicates the presence of a(n)

Question

a. alcohol
b. ether
c. carbonyl
d. amine

Answer 1

The answer is A, an alcohol.

This question is tricky, because both an amine and an alcohol will show up at around 3400 cm^-1 on an IR spec; however, the question specifically asks about which will make a strong signal. Alcohols (oxygens bonded to hydrogens) will show a stronger signal (it is often also a broad peak), whereas amines (nitrogens bonded to hydrogens) will have a medium and sharp peak.