Balance the following half-equations:

CHEMISTRY · Multi-part · A Level · Chemistry · Oxidation, reduction and redox reactions · Oxidation, reduction and redox reactions

Problem

Balance the following half-equations: (1)

\text{SO}_2 \rightarrow \text{SO}_4^{2-}

(2)

\text{MnO}_4^- \rightarrow \text{Mn}^{2+}

(3)

\text{BrO}_3^- \rightarrow \text{Br}_2

(4)

\text{Cr}^{3+} \rightarrow \text{Cr}_2\text{O}_7^{2-}