How many moles of $KMn{O}_4$ are required to oxidize one mole of $SnC{l}_2$ in the acidic medium?

The correct option is B $\frac{2}{5}$

To complete reaction, gram equivalent of both reagent should be same.

Gram eq of $KMn{O}_4$ = Gram equivalent of $SnC{l}_2$

$moles\times V.f.=moles\times V.f.$

$moles\times 5=1\times 2$

$moles=.4$