Q18 / 160 · AP EAMCET 2019 (20 Apr Shift 1) · Chemistry
Sodium acetate was electrolysed by Kolbe's method to form two gases \(A\) and \(B\) at anode. \(C\) and \(D\) are formed, when \(B\) is heated with regulated supply of \(\mathrm{O}_2\) or air in the presence of \(\left(\mathrm{CH}_3 \mathrm{COO}\right)_2 \mathrm{Mn}\). \(\mathrm{C}\) reacts with \(\mathrm{NaOH}\) to form a salt. \(A\) and \(D\) are respectively,
- A\(\mathrm{CO}_2, \mathrm{CH}_3 \mathrm{COOH}\)
- B\(\mathrm{CO}_2, \mathrm{H}_2 \mathrm{O}\)
- Correct answerC\(\mathrm{C}_2 \mathrm{H}_6, \mathrm{H}_2 \mathrm{O}\)
- D\(\mathrm{CO}_2, \mathrm{H}_2 \mathrm{O}_2\)
Solution
Kolbe electrolysis of \(\mathrm{CH}_3 \mathrm{COO}^{-} \mathrm{Na}^{+}\).
At anode,

\(\begin{aligned} & \mathrm{CH}_3^*+\mathrm{CH}_3^* \longrightarrow \mathrm{CH}_3 \underset{(\mathrm{A})}{-\mathrm{CH}_3} \\ & 2 \mathrm{CH}_3-\mathrm{CH}_3+7 \mathrm{O}_2 \stackrel{\left(\mathrm{CH}_3 \mathrm{COO}_2 \mathrm{Mn}\right.}{\longrightarrow} 4 \mathrm{CO}_2+\underset{\mathrm{(D)}}{6 \mathrm{H}_2 \mathrm{O}} \end{aligned}\) \(\mathrm{CO}_2+\mathrm{O}_2 \longrightarrow \underset{\mathrm{(C)}}{\mathrm{CO}}+\mathrm{O}_3\) \(\mathrm{CO}+\mathrm{NaOH} \rightleftharpoons \underset{\text{(Salt)}}{\mathrm{HCOONa}}\) Hence, \(A\) is \(\mathrm{C}_2 \mathrm{H}_6\) and \(D\) is \(\mathrm{H}_2 \mathrm{O}\).

\(\begin{aligned} & \mathrm{CH}_3^*+\mathrm{CH}_3^* \longrightarrow \mathrm{CH}_3 \underset{(\mathrm{A})}{-\mathrm{CH}_3} \\ & 2 \mathrm{CH}_3-\mathrm{CH}_3+7 \mathrm{O}_2 \stackrel{\left(\mathrm{CH}_3 \mathrm{COO}_2 \mathrm{Mn}\right.}{\longrightarrow} 4 \mathrm{CO}_2+\underset{\mathrm{(D)}}{6 \mathrm{H}_2 \mathrm{O}} \end{aligned}\) \(\mathrm{CO}_2+\mathrm{O}_2 \longrightarrow \underset{\mathrm{(C)}}{\mathrm{CO}}+\mathrm{O}_3\) \(\mathrm{CO}+\mathrm{NaOH} \rightleftharpoons \underset{\text{(Salt)}}{\mathrm{HCOONa}}\) Hence, \(A\) is \(\mathrm{C}_2 \mathrm{H}_6\) and \(D\) is \(\mathrm{H}_2 \mathrm{O}\).
Hence, the correct answer is option: 'C'.