Question

Question:Spectra are given for three compounds. Each compound has one or more of the following functional groups: alcohol, amine, ketone, aldehyde, and carboxylic acid. Determine the functional group(s) in each compound, and assign the major peaks above 1600cm^-1.

Short answer

Answer

Step-by-step solution

IR spectroscopy

IR spectroscopy helps detect the functional groups present in the given organic compound. Observe closely the peaks that are obtained in the IR spectrum. Each functional group has a characteristic absorption in IR spectroscopy.

Subpart (a)

If the given spectrum is observed, the peaks are observed at represents the $1660 c{m}^{-1}$ stretch.

A medium peak at$3360 c{m}^{-1}-3200 c{m}^{-1}$ indicates the N-H stretch.

The peaks betweenrole="math" localid="1660720065115" $3000 c{m}^{-1}-2840 c{m}^{-1}$ indicates the presence of C-H stretch.

Hence, the peaks role="math" localid="1660720014870" $1600 c{m}^{-1}$above are N-H stretch, C-H stretch, and C=O stretch.

Subpart (b)

If the given spectrum is observed, a broad peak is observed between $3300 c{m}^{-1}-2500 c{m}^{-1}$, representing the O-H stretch. The peaks between $3000 c{m}^{-1}-2840 c{m}^{-1}$indicates the presence of C-H stretch.

The peak at $31711c{m}^{-1}$indicates the in carboxylic acid.

Thus, the peaks above$1600c{m}^{-1}$ are O-H stretch, C-H stretch, and C=O stretch.

 Step 4: Subpart (c)

If the given spectrum is observed, a broad peak is observed between$3500 c{m}^{-1}-3300 c{m}^{-1}$ , representing the O-H stretch. The peaks between$3000 c{m}^{-1}-2840 c{m}^{-1}$ indicates the presence of C-H stretch.

Thus, the peaks above are O-H stretch, and C-H stretch.