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 :

Let's analyze the chemical half-reaction given:

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

In this half-reaction, we start with copper ions in an aqueous solution, [tex]\( Cu^{2+}(aq) \)[/tex], and these ions gain two electrons, [tex]\( 2e^{-} \)[/tex], to form solid copper, [tex]\( Cu(s) \)[/tex].

To determine what is happening to the copper, we need to understand the two key processes in redox reactions: oxidation and reduction.

1. Oxidation is the loss of electrons, resulting in an increase in oxidation state.
2. Reduction is the gain of electrons, resulting in a decrease in oxidation state.

Given the half-reaction:
[tex]\[ Cu^{2+}(aq) + 2e^{-} \longrightarrow Cu(s) \][/tex]

- The [tex]\( Cu^{2+} \)[/tex] ion is gaining electrons. Specifically, each [tex]\( Cu^{2+} \)[/tex] ion gains 2 electrons to become neutral copper, [tex]\( Cu(s) \)[/tex].
- The gain of electrons is termed as reduction because it reduces the oxidation state of copper from +2 in [tex]\( Cu^{2+} \)[/tex] to 0 in elemental copper [tex]\( Cu(s) \)[/tex].

Now, let's review the given statements to find out which one best describes this process:

- "Copper is being oxidized." (Incorrect, as oxidation would mean losing electrons, which is not the case here.)
- "Copper is being reduced." (Correct, as the copper ion is gaining electrons, which means it is being reduced.)
- "Copper is losing electrons." (Incorrect, the copper ion [tex]\( Cu^{2+} \)[/tex] is gaining electrons, not losing them.)
- "Copper is a reducing agent." (Incorrect in this context, as a reducing agent donates electrons to another species and gets oxidized itself. Here, copper is being reduced, not acting as a reducing agent.)

Hence, the best statement that describes what is taking place is:

Copper is being reduced.