Question

The volume of $0.05M$ $KMn{O}_4$ solution required to oxidize completely $2.70g$ of Oxalic acid $\left(H_2{C}_2{O}_4.2H_{2}O\right)$ in acidic medium will be:

• A. $120cc$
• B. $170cc$
• C. $360cc$
• D. $480cc$

Answer 1

The correct option is B $170cc$

The balanced equation is
$2KMn{O}_4+3H_{2}S{O}_4+5H_{2}C2O_4\to K_{2}S{O}_4+2MnS{O}_4+8H_{2}O+10C{O}_2$
5 moles of oxalic acid react with 2 moles of $KMn{O}_4$
$2.70g$ of oxalic acid = $\frac{270}{126}$ mole
$\frac{270}{126}$ moles of oxalic acid react with
$KMn{O}_4=\frac{2}{5}\times \frac{2.70}{126}=0.008571$ mole

0.05 moles of $KMn{O}_4$ Solution is present in $1000cc$

0.008571 mole of $KMn{O}_4$ will be present in $\frac{1000}{0.05}\times 0.008571=171cc$