Question

Predict the appearance of the high-resolution proton NMR spectrum of propanoic acid.

Short answer

The high-resolution proton NMR spectrum of propanoic acid will have three peaks. It will have one singlet, one triplet and one quadruplet peak.

Step-by-step solution

Concept:

In a high resolution spectra the number of peaks tells the number of different environments the hydrogen atoms are in the compound. And the ratio of the areas under the peaks tells the ratio of the numbers of hydrogen atoms in each of these environments. Based on number of hydrogen electrons in adjacent carbon the peak is split.

Description:

A high resolution spectra of propanoic acid show 3 groups of proton resonances and in the 3:2:1 ratio as from the formula of propanoic acid.

The figure below explains the peaks on the spectrum.