Question

Consider the reaction below.

Upper Z n (s) plus upper C u superscript 2 plus (a q) right arrow upper Z n superscript 2 plus (a q) plus upper C u (s).

Which half reaction correctly describes the oxidation that is taking place?
Z n (s) right arrow upper Z n superscript 2 plus (a q) plus e superscript minus.
Upper Z n (s) right arrow upper Z n superscript 2 plus (a q) plus 2 e superscript minus.
Upper C u superscript 2 plus (a q) plus 2 e superscript minus right arrow upper C u (s).
Upper C u superscript 2 plus (a q) plus e superscript minus right arrow upper C u (s).

Answer 1

The oxidation half-reaction is:
Zn(s) → Zn2+(aq) + 2 e−

Zinc is oxidized (its oxidation state goes from 0 to +2), so it loses two electrons.