Question

3. Write down balanced ionic equations to show the reactions that take place at the:

(i) Anode


(ii) Cathode

Answer 1

$1. \ Zn_{(s)} + Cu^{2+}_{(aq)} \rightarrow Zn^{(2+)}_{(aq)} + Cu_{(s)}$

(i)Anode oxidation reaction

$Zn_{(s)} \rightarrow Zn^{2+}_{(aq)} + 2e^-$

(ii)Cathode reduction reaction

$Cu_{(aq)}^{2+} + 2e^- \rightarrow Cu_{(s)}$

$2. \ Zn_{(s)} + Br_{2(aq)} \rightarrow Zn^{2+}_{(aq)} + 2Br^-_{(aq)}$

Anode oxidation reaction

(i)$Zn_{(s)} \rightarrow Zn^{2+}_{(aq)} + 2e^-$

(ii) Cathode reduction reaction

$Br_{2(aq)} + 2e^- \rightarrow 2Br^-_{(aq)}$