In the following balanced reaction, values of $X, Y$ and $Z$ respectively are

In the following balanced reaction,
values of $X, Y$ and $Z$ respectively are
  1. 2,5,16
  2. $8,2,5$
  3. $5,2,16$
  4. $5,8,4$

Solution

$X \mathrm{MnO}_4^{-}+Y \mathrm{C}_2 \mathrm{O}_4^{-}+Z \mathrm{H}^{+} \leftrightharpoons$ $ X \mathrm{Mn}^{++}+2 Y \mathrm{CO}_2+\frac{Z}{2} \mathrm{H}_2 \mathrm{O} $ First half reaction $ \mathrm{MnO}_4^{-} \longrightarrow \mathrm{Mn}^{++} $ On balancing $ \mathrm{MnO}_4^{-}+8 \mathrm{H}^{+}+5 \mathrm{e}^{-} \longrightarrow \mathrm{Mn}^{++}+4 \mathrm{H}_2 \mathrm{O} $ Second half reaction $ \mathrm{C}_2 \mathrm{O}_4^{-} \longrightarrow 2 \mathrm{CO}_2 $ On balancing $ \mathrm{C}_2 \mathrm{O}_4^{-} \longrightarrow 2 \mathrm{CO}_2+2 \mathrm{e}^{-} $ On multiplying eqn. (ii) by 5 and (iv) by 2 and then adding we get $ \begin{aligned} & 2 \mathrm{MnO}_4^{-}+5 \mathrm{C}_2 \mathrm{O}_4^{--}+16 \mathrm{H}^{+} \longrightarrow \\ & 2 \mathrm{Mn}^{++}+10 \mathrm{CO}_2+8 \mathrm{H}_2 \mathrm{O} \end{aligned} $

Asked in: JEE Main 2012 (12 May Online)

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