Question

what is the stretching frequency (in cm⁻¹) of the following carbonyl?
none of the above
1745
1715
1655
1685

Explanation:

Step1: Identify the carbonyl type

The given compound is an aromatic ester. Aromatic esters have carbon - oxygen double - bond ($C=O$) stretching frequencies in a characteristic range.

Step2: Recall the frequency range

The $C=O$ stretching frequency of aromatic esters is approximately $1715 - 1730\ cm^{-1}$.

Answer:

1715