Question

$100$ mL of $0.01M$ $KMn{O}_4$ oxidised $100$ mL $H_2{O}_2$ in acidic medium. The volume of same $KMn{O}_4$ required in strong alkaline medium to oxidise $100$ mL of same $H_2{O}_2$ is :

• A. $\frac{100}{3}mL$
• B. $\frac{500}{3}mL$
• C. $\frac{300}{5}mL$
• D. none of these

Answer 1

The correct option is D none of these

In acidic medium : mEq. of $KMn{O}_4\equiv$ mEq. of $H_2{O}_2$
$(0.01\times 5)\times 100\equiv N\times 100$ ...(i)
In basic medium: mEq. of $KMn{O}_4\equiv$ mEq. of $H_2{O}_2$
$\left[Mn{O}_4^{⊝}\stackrel{\stackrel{⊝}{O}H}{\underset{strong}{\to }}Mn{O}_4^{2-}\right]$
$(0.01\times 1)\times V=N\times 100$ .....(ii)
From equations (i) and (ii), we get
$(0.01\times 1)\times V\equiv (0.01\times 5)\times 100\Rightarrow V=500$ mL.