Question

which of the structures have a major peak between 1700 and 3000 cm⁻¹? (select all that apply). none of these

Explanation:

Alkynes have a C - C triple - bond stretching vibration peak in the range of 2100 - 2260 $cm^{-1}$, which is between 1700 and 3000 $cm^{-1}$. Aromatic C - H out - of - plane bending for monosubstituted chlorobenzene is not in this range. The carbonyl stretching of esters is around 1735 - 1750 $cm^{-1}$, also in the range.

Answer:

The first structure (alkyne), the fourth structure (ester)