Chemistry - s Block Elements Question with Solution | TestHub

When ${\mathrm{Na}}_2{\mathrm{SO}}_3$ reacts with hot and dil ${\mathrm{H}}_2{\mathrm{SO}}_4,$ it gives ${\mathrm{SO}}_2\left(\mathrm{g}\right)$ which decolourises bromine-water.

The reaction proceed as follows:

(i) ${\mathrm{Na}}_2{\mathrm{SO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4⟶{\mathrm{Na}}_2{\mathrm{SO}}_4+{\mathrm{SO}}_2+{\mathrm{H}}_2\mathrm{O}$

(ii) ${\mathrm{Br}}_2+{\mathrm{H}}_2\mathrm{O}⟶2\mathrm{HBr}+\left[\mathrm{O}\right]$

(iii) ${\mathrm{SO}}_2+\left[\mathrm{O}\right]⟶{\mathrm{SO}}_3$ (decolourisation of bromine-water)