Question

Which of the following statements are correct?

(i) The electrolysis of aqueous NaCl produces hydrogen gas at the cathode and chlorine gas at the anode

(ii) The electrolysis of a $CuS{O}_4$ solution using Pt electrodes causes the liberation of $O_2$ at the anode and the deposition of copper at the cathode

(iii) Oxygen and hydrogen are produced at the anode and cathode during the electrolysis of dilute aqueous solution of $H_{2}S{O}_4$

(iv) All electrolytic reactions are redox reactions

• A. Only (i) is correct
• B. (i), (ii) are correct
• C. (i), (iv) are correct
• D. All are correct

Answer 1

The correct option is D All are correct

For aqueous NaCl solution reactions
At Anode :
$2C{l}^{-}\to {\mathrm{Cl}}_2+2e^{-}$
At Cathode : $2H_{2}O+2e⁻\to H_2+2O{H}^{-}$

For aqueous $CuS{O}_4$ solution
At Anode : Cu (s) → Cu⁺²(aq) + 2 e⁻
At cathode : Cu⁺²(aq) + 2 e⁻ → Cu (s)

For aqueous solution of $H_{2}S{O}_4$ simple electrolysis of water takes place.
At Anode : $2H_{2}O\to O_2+4H^{+}+4e⁻$
At Cathode : $2H_{2}O+2e⁻\to H_2+2O{H}^{-}$