Chemistry - GOC Question with Solution | TestHub

Removing H₁ puts the negative charge on the -NH₂ nitrogen :

Removing H₂ puts the negative charge on the -NHCH₃ nitrogen :

In both cases the charge is on nitrogen with no resonance, so compare induction : the methyl group donates electron density and destabilises the second anion. The first conjugate base is more stable, so the N-H proton of the -NH₂ group, H₁, is more acidic.