Chemistry - Salt Analysis Question with Solution | TestHub

Gas (Y) ${\mathrm{SO}}_2$ which can be obtained from ${\mathrm{Na}}_2{\mathrm{SO}}_3(\mathrm{A})$ and gas $(\mathrm{Z})$ is ${\mathrm{H}}_2\mathrm{S}$ which can be obtained from ${\mathrm{Na}}_2\mathrm{S}(\mathrm{B})$. This can be easily understood by the following reactions. $$\begin{array}{rl}& {\mathrm{Na}}_2{\mathrm{SO}}_3+2\mathrm{HCl}\to 2\mathrm{NaCl}+{\mathrm{SO}}_2+{\mathrm{H}}_2\mathrm{O}\\ & (\mathrm{A})\\ & (\mathrm{Y})\\ & {\mathrm{Na}}_2\mathrm{S}+2\mathrm{HCl}\to 2\mathrm{NaCl}+{\mathrm{H}}_2\mathrm{S}\\ & (\mathrm{B})\\ {\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7+{\mathrm{H}}_2{\mathrm{SO}}_4+3{\mathrm{SO}}_2& \to {\mathrm{K}}_2{\mathrm{SO}}_4\\ & +{\mathrm{Cr}}_2{\left({\mathrm{SO}}_4\right)}_3+{\mathrm{H}}_2\mathrm{O}\\ \mathrm{Pb}{\left({\mathrm{CH}}_3\mathrm{COO}\right)}_2+{\mathrm{H}}_2\mathrm{S}\to & {\mathrm{PbS}}_{\downarrow }\downarrow +2{\mathrm{CH}}_3\mathrm{COOH}\\ & \text{ black }\end{array}$$