Chemistry - GOC Question with Solution | TestHub

Removing ${\mathrm{H}}_1$ gives the sulfonate :

Removing ${\mathrm{H}}_2$ gives the nitrogen anion :

Factor (1) atom : oxygen holds the negative charge better than nitrogen, and the sulfonate is further stabilised by resonance over the sulfonyl oxygens. The O-H proton ${\mathrm{H}}_1$ is more acidic.