Consider the half reactions below for a chemical reaction. ZnZn2+ (aq) + 2e
Cu?" (aq) + 2e → Cu(s)
What is the overall equation for this chemical reaction?
Zn(s)+ Cu?* (aq) —>Zn2+ (aq) + Cu(s)
O Zn(s) + Cu2+ (aq) — Cu2+ (aq) + 2e-
O Zn2*(aq) + Cu(s) —> Cu2* (aq) + Zn(s)
O Zn2+ (aq) + 22 —> Cu2(aq) + 2e

Option A:

Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)

Explanation:

The half reactions given are:

Zn(s) → Zn^(2+)(aq) + 2e^(-)

Cu^(2+) (aq) + 2e^(-) → Cu(s)

From the given half reactions, we can see that in the first one, Zn undergoes oxidation to produce Zn^(2+).

While in the second half reaction, Cu^(2+) is reduced to Cu.

Thus, for the overall reaction, we will add both half reactions to get;

Zn(s) + Cu^(2+) (aq) + 2e^(-) → Cu(s) + Zn^(2+)(aq) + 2e^(-)

2e^(-) will cancel out to give us;

Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)