Chemistry - Electrochemistry Question with Solution | TestHub

At the anode, oxidation takes place. Oxidation is defined as the loss of electrons.

Analyzing the given reactions:

${\text{F}}_2+2e^{-}\to 2{\text{F}}^{-}$ involves the gain of electrons, hence it is a reduction reaction.

$2{\text{H}}^{+}+\frac{1}{2}{\text{O}}_2+2e^{-}\to {\text{H}}_2\text{O}$ involves the gain of electrons, hence it is a reduction reaction.

${\text{Fe}}^{2+}\to {\text{Fe}}^{3+}+1e^{-}$ involves the loss of an electron, hence it is an oxidation reaction.

${\text{Cu}}^{2+}+2e^{-}\to \text{Cu}(s)$ involves the gain of electrons, hence it is a reduction reaction.

Since only the third reaction represents oxidation, it is the only reaction possible at the anode.

Answer: ${\text{Fe}}^{2+}\to {\text{Fe}}^{3+}+1e^{-}$