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## AP®︎/College Chemistry

### Course: AP®︎/College Chemistry>Unit 4

Lesson 5: Oxidation–reduction (redox) reactions

# Oxidation–reduction (redox) reactions

## Problem

$\begin{array}{rl}& \text{Oxidation:}\phantom{\rule{1em}{0ex}}\mathrm{Cu}\left(s\right)\to \mathrm{Cu}{\phantom{A}}^{2+}\left(aq\right)+2\phantom{\rule{0.167em}{0ex}}{e}^{-}\\ & \text{Reduction:}\phantom{\rule{1em}{0ex}}\mathrm{MnO}{\phantom{A}}_{4}{\phantom{A}}^{-}\left(aq\right)+4\phantom{\rule{0.167em}{0ex}}\mathrm{H}{\phantom{A}}^{+}\left(aq\right)+3\phantom{\rule{0.167em}{0ex}}{e}^{-}\to \mathrm{MnO}{\phantom{A}}_{2}\left(s\right)+2\phantom{\rule{0.167em}{0ex}}\mathrm{H}{\phantom{A}}_{2}\mathrm{O}\left(l\right)\end{array}$
When the half-reactions listed above are combined into a balanced chemical equation, the ratio of the coefficients $\mathrm{Cu}\left(s\right):\mathrm{MnO}{\phantom{A}}_{4}{\phantom{A}}^{-}\left(aq\right)$ is