Chemistry - GOC Question with Solution | TestHub

Removing ${\mathrm{H}}_1$ puts the negative charge on oxygen :

Removing ${\mathrm{H}}_2$ puts the negative charge on nitrogen :

Nitrogen and oxygen are in the same period, so compare electronegativity : oxygen stabilises the negative charge better than nitrogen. The alkoxide is the more stable conjugate base, so the O-H proton ${\mathrm{H}}_1$ is more acidic.