Question

The reaction of an inorganic Sulphite $\mathrm{X}$ with dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$ generates compound $\mathrm{Y}$. Reaction of $\mathrm{Y}$ with $\mathrm{NaOH}$ gives $\mathrm{X}$. Further, the reaction of $\mathrm{X}$ with $\mathrm{Y}$ and water affords compound $\mathrm{Z}$. $\mathrm{Y}$ and $\mathrm{Z}$, respectively, are :

• A. ${\mathrm{SO}}_2$and ${\mathrm{NaHSO}}_3$
• B. $\mathrm{S}$ and ${\mathrm{Na}}_2{\mathrm{SO}}_3$
• C. ${\mathrm{SO}}_2$ and ${\mathrm{Na}}_2{\mathrm{SO}}_3$
• D. ${\mathrm{SO}}_3$ and ${\mathrm{NaHSO}}_3$

Answer 1

The correct option is A

${\mathrm{SO}}_2$and ${\mathrm{NaHSO}}_3$

Explanation for Correct answer:

Option (A) ${\mathrm{SO}}_2$and ${\mathrm{NaHSO}}_3$

• The reaction of Sodium sulphite (${\mathrm{Na}}_2{\mathrm{SO}}_3$) with dilute Sulphuric acid(${\mathrm{H}}_2{\mathrm{SO}}_4$) generates a compound of Sulphur dioxide(${\mathrm{SO}}_2$).

$\underset{\mathrm{Sodium}\mathrm{suphite}}{{\mathrm{Na}}_2{\mathrm{SO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{dil}.\mathrm{Sulphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}\to \underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}+\underset{\mathrm{Sulphur}\mathrm{dioxide}}{{\mathrm{SO}}_2\left(\mathrm{g}\right)}$

• The reaction of Sulphur dioxide(${\mathrm{SO}}_2$) with ($\mathrm{NaOH}$) gives Sodium sulphite (${\mathrm{Na}}_2{\mathrm{SO}}_3$).

$\underset{\mathrm{Sulfur}\mathrm{dioxide}}{{\mathrm{SO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Sodium}\mathrm{hydroxide}}{\mathrm{NaOH}\left(\mathrm{aq}\right)}\to \underset{\mathrm{Sodium}\mathrm{sulphite}}{{\mathrm{Na}}_2{\mathrm{SO}}_3\left(\mathrm{aq}\right)}$

• The reaction of Sodium sulphite(${\mathrm{Na}}_2{\mathrm{SO}}_3$) with Sulphur dioxide(${\mathrm{SO}}_2$) and water afford the compound Sodium bisulfite(${\mathrm{NaHSO}}_3$).

$\underset{\mathrm{Sulfur}\mathrm{dioxide}}{{\mathrm{SO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Sodium}\mathrm{sulphite}}{{\mathrm{Na}}_2{\mathrm{SO}}_3\left(\mathrm{s}\right)}\to \underset{\mathrm{Sodium}\mathrm{bisulphate}}{{\mathrm{NaHSO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

• Therefore, $\mathrm{X}$ is ${\mathrm{Na}}_2{\mathrm{SO}}_3$, $\mathrm{Y}$is ${\mathrm{SO}}_2$and $\mathrm{Z}$ is ${\mathrm{NaHSO}}_3$.
• Hence correct option.