Which of the following will be applied when a metal Y is used to electroplate another metal X in electrolysis?

Analyze the question: Metal Y is used to coat (electroplate) metal X. We need to identify which electrode is which.

Concept: In electroplating:

• The object to be plated is the cathode (negative electrode). Metal ions are reduced and deposited on it.
• The plating metal is the anode (positive electrode). It dissolves into the electrolyte, replacing the ions that get deposited.
• The electrolyte contains a salt of the plating metal.

Applying it here:

• X is the object being plated, so X is the cathode.
• Y is the plating metal, so Y is the anode.

Checking the options:

• A. X is the anode: wrong, since X should be the cathode.
• B. X is the anode and Y is the cathode: wrong, since it is reversed.
• C. Y is the cathode and X is the anode: wrong, since it is also reversed.
• D. Y is the anode and a very high current is used: the electrode assignment is correct (Y anode, so X is the cathode). The "very high current" part is not ideal in practice, because a smooth, adherent coating needs a moderate, controlled current. Even so, it is the only option with Y as the anode.

The "very high current" wording is a weakness in the question itself, but the electrode assignment is what the examiner is testing.

Answer: D

Exam tip: Remember "Cathode = Coat me", meaning the object to be coated is the cathode. The plating metal is always the anode. When options are imperfect, choose the one whose key concept (electrode roles) is correct.