Question

The number of mole of oxalate ions oxidised by one mole of $Mn{O}_4^{-}$ is :

• A. 1/5
• B. 2/5
• C. 5/2
• D. 5

Answer 1

The correct option is D 5

$M{n}^{7+}+5e^{-}⟶M{n}^{2+}$

$(C^{+3}{)}_2$ $⟶2C^{4+}+2e^{-}$
$2Mn{O}_4^{-}+5C_2{O}_4^{2-}\to 5C{O}_2+2M{n}^{2+}$

1 mole of$Mn{O}_4^{-}⟶$ 5 mole of $e^{-}$

1 mole of $C_2{O}_4^{2-}⟶$ 2 mole of $e^{-}$

$\frac{5\times 1}{2}{C}_2{O}_4^{2-}⟶$ 5 mole of $e^{-}$

The number of mole of oxalate ions oxidised by one mole of $Mn{O}_4^{-}$ is $\frac{5}{2}$

Hence, option C is correct.