In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode
Anode Cathode
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
Correct Answer: Option C
Explanation:
Electrolysis of Dilute Sulphuric Acid (H₂SO₄) using Platinum Electrodes:
When dilute H₂SO₄ is electrolyzed, the ions present in solution are:
- H⁺ and SO₄²⁻ from the acid
- H₂O molecules (water itself ionizes slightly into H⁺ and OH⁻)
---
At the Cathode (−):
- Reduction occurs.
- H⁺ ions are discharged, gaining electrons to form hydrogen gas (H₂):
\[
2H^+ + 2e^- \rightarrow H_2(g)
\]
At the Anode (+):
- Oxidation occurs.
- OH⁻ ions (from water) are discharged preferentially over SO₄²⁻, releasing oxygen gas (O₂):
\[
4OH^- \rightarrow 2H_2O + O_2(g) + 4e^-
\]
---
Final Products:
- Hydrogen gas at the cathode
- Oxygen gas at the anode
Answer: C. Oxygen — Hydrogen
Electrolysis of Dilute Sulphuric Acid (H₂SO₄) using Platinum Electrodes:
When dilute H₂SO₄ is electrolyzed, the ions present in solution are:
- H⁺ and SO₄²⁻ from the acid
- H₂O molecules (water itself ionizes slightly into H⁺ and OH⁻)
---
At the Cathode (−):
- Reduction occurs.
- H⁺ ions are discharged, gaining electrons to form hydrogen gas (H₂):
\[
2H^+ + 2e^- \rightarrow H_2(g)
\]
At the Anode (+):
- Oxidation occurs.
- OH⁻ ions (from water) are discharged preferentially over SO₄²⁻, releasing oxygen gas (O₂):
\[
4OH^- \rightarrow 2H_2O + O_2(g) + 4e^-
\]
---
Final Products:
- Hydrogen gas at the cathode
- Oxygen gas at the anode
Answer: C. Oxygen — Hydrogen