Chemistry 9701/12 — October/November 2012

In which reaction does an element undergo the largest change in oxidation state?

Options

A   $\text{Cl}_2 + 2\text{OH}^- \rightarrow \text{OCl}^- + \text{Cl}^- + \text{H}_2\text{O}$

B   $3\text{Cl}_2 + 6\text{OH}^- \rightarrow \text{ClO}_3^- + 5\text{Cl}^- + 3\text{H}_2\text{O}$

C   $\text{Cr}_2\text{O}_7^{2-} + 6\text{Fe}^{2+} + 14\text{H}^+ \rightarrow 2\text{Cr}^{3+} + 6\text{Fe}^{3+} + 7\text{H}_2\text{O}$

D   $3\text{MnO}_4^{2-} + 4\text{H}^+ \rightarrow \text{MnO}_2 + 2\text{MnO}_4^- + 2\text{H}_2\text{O}$