Consider the half-reaction below:

[tex]Cu^{2+}(aq) + 2e^{-} \longrightarrow Cu(s)[/tex]

Which statement best describes what is taking place?

A. Copper is being oxidized.
B. Copper is being reduced.
C. Copper is losing electrons.
D. Copper is a reducing agent.



Answer :

To solve the question regarding the half-reaction given, we need to analyze what is happening to the copper species in the reaction:

[tex]\[ Cu^{2+}(aq) + 2e^{-} \rightarrow Cu(s) \][/tex]

1. Identify the Elements Involved:
- Cu^{2+}: Copper ion in aqueous solution, which has a +2 charge.
- e^{-}: Electrons.
- Cu(s): Solid copper with no charge.

2. Determine the Change in Charges:
- The copper ion, Cu^{2+}, has a +2 charge.
- The solid copper, Cu(s), is in its elemental form and has a 0 charge.

3. Understanding the Electron Transfer:
- The Cu^{2+} ion is gaining 2 electrons ([tex]\(2e^{-}\)[/tex]) to become neutral copper ([tex]\(Cu\)[/tex]).
- The gain of electrons by a species is referred to as reduction.

4. Define Oxidation and Reduction:
- Oxidation is the loss of electrons.
- Reduction is the gain of electrons.

5. Apply the Definitions:
- Since Cu^{2+} is gaining electrons ([tex]\(2e^{-}\)[/tex]), it is undergoing reduction.

6. Evaluate the Other Three Statements:
- Copper is being oxidized: This statement is incorrect because oxidation involves losing electrons, whereas copper is gaining electrons.
- Copper is losing electrons: This statement is incorrect because copper is gaining, not losing, electrons.
- Copper is a reducing agent: This statement is incorrect because a reducing agent donates electrons to another species and itself gets oxidized. Here, copper is the one gaining electrons, so it is not acting as a reducing agent.

Therefore, the correct description of what is taking place is:

Copper is being reduced.

In conclusion, the second statement, "Copper is being reduced," is the correct answer.