4.2 Exercise 28

Balance each of the following equations according to the half-reaction method:

(a) $\text{Sn}^{2+} \left(a q\right) + \text{Cu}^{2+} \left(a q\right) \rightarrow \text{Sn}^{4+} \left(a q\right) + \text{Cu}^{+} \left(a q\right)$

(b) $\text{H}_{2} \text{S} \left(g\right) + \text{Hg}_{2} ^{2+} \left(a q\right) \rightarrow \text{H} g \left(l\right) + \text{S} \left(s\right) (\text{in acid})$

(c) $\text{CN}^{−} \left(a q\right) + \text{ClO}_{2} \left(a q\right) \rightarrow \text{CNO}^{−} \left(a q\right) + \text{Cl}^{−} \left(a q\right) (\text{in acid})$

(d) $\text{Fe}^{2+} \left(a q\right) + \text{Ce}^{4+} \left(a q\right) \rightarrow \text{Fe}^{3+} \left(a q\right) + \text{Ce}^{3+} \left(a q\right)$

(e) $\text{HBrO} \left(a q\right) \rightarrow \text{Br}^{−} \left(a q\right) + \text{O}_{2} \left(g\right) (\text{in acid})$