$$2 \mathrm{MnO}_4^{-}+\mathrm{bI}^{-}+\mathrm{cH}_2 \mathrm{O} \rightarrow x \mathrm{I}_2+y \mathrm{MnO}_2+z \overline{\mathrm{O}} \mathrm{H}$$
If the above equation is balanced with integer coefficients, the value of $z$ is ________.
Answer (integer)
8
Solution
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<th class="tg-amwm">Reduction Half</th>
<th class="tg-amwm">Oxidation Half</th>
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</thead>
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<tr>
<td class="tg-baqh">$2 \mathrm{MnO}_4^{-} \rightarrow 2 \mathrm{MnO}_2$</td>
<td class="tg-baqh">$2 \mathrm{I}^{-} \rightarrow \mathrm{I}_2+2 \mathrm{e}^{-}$</td>
</tr>
<tr>
<td class="tg-baqh">$$2 \mathrm{MnO}_4^{-}+4 \mathrm{H}_2 \mathrm{O}+6 \mathrm{e}^{-} \rightarrow 2 \mathrm{MnO}_2+8 \mathrm{OH}^{-}$$</td>
<td class="tg-baqh">$6 \mathrm{I}^{-} \rightarrow 3 \mathrm{I}_2+6 \mathrm{e}^{-}$</td>
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<p>Adding oxidation half and reduction half, net reaction is</p>
<p>$$\begin{aligned}
& 2 \mathrm{MnO}_4^{-}+6 \mathrm{I}^{-}+4 \mathrm{H}_2 \mathrm{O} \rightarrow 3 \mathrm{I}_2+2 \mathrm{MnO}_2+8 \mathrm{OH}^{-} \\
\Rightarrow \quad & \mathrm{z}=8 \\
\Rightarrow \quad & \text { Ans } 8
\end{aligned}$$</p>
About this question
Subject: Chemistry · Chapter: Redox Reactions · Topic: Oxidation States
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