Question

O\(_2\) gas will be evolved as a product of electrolysis of: 
(A) an aqueous solution of AgNO3 using silver electrodes. 
(B) an aqueous solution of AgNO3 using platinum electrodes. 
(C) a dilute solution of H2SO4 using platinum electrodes. 
(D) a high concentration solution of H2SO4 using platinum electrodes. 
Choose the correct answer from the options given below :

• (B) and (C) only
• (A) and (D) only
• (B) and (D) only
• (A) and (C) only

Hint:

Oxygen gas is evolved at the anode during electrolysis when water or dilute sulfuric acid is electrolyzed. At high concentrations of sulfuric acid, hydrogen gas evolution is favored at the anode.

Answer 1

The Correct Option is A

Oxygen gas (O\(_2\)) is generated at the anode during water or aqueous solution electrolysis under specific conditions.

(A) Aqueous AgNO\(_3\) with silver electrodes: Silver ions reduce to silver metal at the cathode. The silver anode oxidizes to form silver ions, preventing oxygen gas production at the anode. Consequently, no O\(_2\) is released.

(B) Aqueous AgNO\(_3\) with platinum electrodes: Platinum electrodes are inert. Electrolysis of AgNO\(_3\) with platinum electrodes results in oxygen gas evolution at the anode due to water oxidation. This is accurate.

(C) Dilute H\(_2\)SO\(_4\) with platinum electrodes: In this scenario, water acts as the primary electrolyte. Electrolysis of dilute sulfuric acid produces oxygen gas at the anode. This is accurate.

(D) Concentrated H\(_2\)SO\(_4\) with platinum electrodes: High concentrations of H\(_2\)SO\(_4\) inhibit oxygen evolution; hydrogen gas is more likely to form at the anode. This is incorrect regarding oxygen evolution.

Therefore, the correct options are (1) (B) and (C) exclusively.