Question

The ratio of number of moles of $KMn{O}_4$ and $K_{2}C{r}_2{O}_7$ required to oxidise $0.1molS{n}^{2+}$ to $S{n}^{+4}$ in acidic medium is _____.

• A. $6:5$
• B. $5:6$
• C. $1:2$
• D. $2:1$

Answer 1

The correct option is A $6:5$

Gram equivalent must be same,

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

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

$moles\times 5=.1\times 2$

$moles=\frac{.1\times 2}{5}$

for $K_{2}C{r}_2{O}_7$-

gram eq of $K_{2}C{r}_2{O}_7$ = Gram eq $SnC{l}_2$

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

$moles\times 6=.1\times 2$

$moles=\frac{.1\times 2}{6}$

SO the ratio is $\frac{6}{5}.$