O2 gas will be evolved as a product of electrolysis of :

Question

\(\mathrm{O}_2\) gas will be evolved as a product of electrolysis of :

(A) an aqueous solution of \(\mathrm{AgNO}_3\) using silver electrodes.

(B) an aqueous solution of \(\mathrm{AgNO}_3\) using platinum electrodes.

(C) a dilute solution of \(\mathrm{H}_2 \mathrm{SO}_4\) using platinum electrodes.

(D) a high concentration solution of \(\mathrm{H}_2 \mathrm{SO}_4\) using platinum electrodes.

Choose the correct answer from the options given below :

(1) (B) and (C) only

(2) (A) and (D) only

(3) (B) and (D) only

(4) (A) and (C) only

Answer 1

Correct option is (1) (B) and (C) only

When an aqueous solution of \(\mathrm{AgNO}_3\) is electrolysed using Pt electrodes

Cathode: \(\mathrm{Ag}^{+}(\mathrm{aq})+\mathrm{e}^{-} \rightarrow \mathrm{Ag}(\mathrm{s})\)

Anode : \(2 \mathrm{H}_2 \mathrm{O}(\mathrm{l}) \rightleftharpoons 4 \mathrm{H}^{+} (\mathrm{aq})+\mathrm{O}_2(\mathrm{~g})+4 \mathrm{e}^{-}\)

\(\Rightarrow\) When dilute \(\mathrm{H}_2 \mathrm{SO}_4\) is electrolysed using Pt electrodes

Anode : \(2 \mathrm{H}_2 \mathrm{O}(\mathrm{I}) \rightarrow \mathrm{O}_2(\mathrm{~g})+4 \mathrm{H}^{+}(\mathrm{aq})+4 \mathrm{e}^{-}\)    

Cathode : \(2 \mathrm{H}^{+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow \mathrm{H}_2(\mathrm{~g})\)