Question

which reaction occurs at the anode in an electrochemical cell?
a. zn(s) + cu²⁺(aq) → zn²⁺(aq) + cu(s)
b. zn²⁺(aq) + cu(s) → zn(s) + cu²⁺(aq)
c. zn²⁺(aq) + 2e⁻ → zn(s)
d. zn(s) → zn²⁺(aq) + 2e⁻

Explanation:

In an electrochemical cell, oxidation occurs at the anode. Oxidation is the loss of electrons. In option D, zinc metal (Zn) loses two electrons to form zinc - ions ($Zn^{2 + }$), which is an oxidation reaction.

Answer:

D. $Zn(s)
ightarrow Zn^{2 + }(aq)+2e^{-}$