Question

Consider the following reaction:
$x \, MnO_{4}^{-}+y \, C_{2}O_{4}^{2 -}+zH^{+} \rightarrow x \, Mn^{2 +}+2y \, CO_{2}+\frac{z}{2}H_{2}O$
The values of x, y and z in the reaction are, respectively:

• A. $2,5and16$
• B. $5,2and8$
• C. $5,2and16$
• D. $2,5and8$

Answer 1

Answer: (A)

$\text{C}_{2}\text{O}_{4}^{2 -} & \rightarrow & 2\text{CO}_{2}+2\text{e}^{-}\left]\right.\times 5 \\ \text{MnO}_{4}^{-}+8\text{H}^{+}+5\text{e}^{-} & \rightarrow & \text{Mn}^{2 +}+4\text{H}_{2}\text{O}\left]\right.\times 2$
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$2\text{MnO}_{4}^{-}+16\text{H}^{+}+5\text{C}_{2}\text{O}_{4}^{2 -} & \rightarrow 1 0 \text{CO}_{2} + 2 \text{Mn}^{2 +} + 8 \text{H}_{2} \text{O}$
$\text{MnO}_{4}^{-} \Rightarrow \text{x} = 2$
$\text{C}_{2} \text{O}_{4}^{2 -} \Rightarrow \text{y} = 5$
$\text{H}^{+} \Rightarrow \text{z} = 1 6$