Acidified potassium permanganate solution oxidises oxalic acid. The...

$2{KMnO}_{4} + 5{H}_{2}{C}_{2}{O}_{4} + 3{H}_{2}{SO}_{4} \to {K}_{2}{SO}_{4} + 2{MnSO}_{4} + 10{CO}_{2} + 8{H}_{2}O$

In acidic medium, ${Mn}^{7 +}$ gets reduced to ${Mn}^{2 +}$

Mn (II) $= \left[Ar\right]3{d}^{5}$

Number of unpaired electron in ${Mn}^{2 +} = 5$

$\mu = \sqrt{n\left(n + 2\right)}B . M$

$\mu = \sqrt{5\left(5 + 2\right)}B . M$

$\mu = 5 . 9B . M$