Question

Which from following is NOT correct regarding electrolysis?

• A. It helps in refining of metals.
• B. Conversion of electrical energy into chemical energy takes place.
• C. It is useful in electroplating.
• D. Metal is deposited at anode.

Hint:

Remember the classic mnemonic: Red Cat (Reduction happens at the Cathode). Since gaining electrons to turn metal ions into solid metal atoms is a reduction process, it must happen exclusively at the cathode!

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
We need to examine four conceptual statements concerning electrochemical electrolytic cells and select the single incorrect (false) statement.

Step 2: Detailed Explanation:
Let's analyze the operational mechanics of an electrolytic cell:

• Option (A): Electrolysis is universally used in the electrometallurgical refining of impure metals (e.g., copper refining), where pure metal builds up on one electrode. This statement is correct.

• Option (B): An electrolytic cell uses an external electrical power source to drive a non-spontaneous chemical reaction. Thus, it converts electrical energy into chemical energy. This statement is correct.

• Option (C): Electroplating relies completely on electrolysis to deposit a thin protective or decorative layer of a metal onto a conducting surface. This statement is correct.

• Option (D): During electrolysis, positive metal cations ($\text{M}^{n+}$) migrate toward the negatively charged electrode, which is the

cathode. At the cathode, these ions undergo reduction by gaining electrons to deposit as solid metal grains: $$ \text{M}^{n+} + n\text{e}^- \longrightarrow \text{M}_{(s)} \quad (\text{at Cathode}) $$ The anode is the site of oxidation, where an electrode typically dissolves or non-metals evolve. Therefore, stating that metal deposits at the anode is completely incorrect.


Step 3: Final Answer: The incorrect statement regarding electrolysis is option (D).