Question

A $5.0c{m}^3$ solution of $H_2{O}_2$ liberates $0.508$ g of $I_2$ from an acidified $KI$ solution. The strength of $H_2{O}_2$ solution in terms of volume strength at STP is:

• A. 2.24 V
• B. 1.12 V
• C. 4.48 V
• D. 8.96 V

Answer 1

The correct option is C 4.48 V

$2KI+H_{2}S{O}_4+H_2{O}_2\to K_{2}S{O}_4+2H_{2}O+I_2$

Hence, the number of moles of $H_2{O}_2=$ number of moles of iodine $=\frac{0.508g}{253.8g/mol}=2.00\times {10}^{-3}mol$

The molarity of $H_2{O}_2$ solution is $\frac{2.00\times {10}^{-3}mol}{5.0\times {10}^{-3}L}=0.4M$

The volume strength of hydrogen peroxide is 11.2 times its molarity.

It is equal to $11.2\times 0.4=4.48V$.

Hence, option C is correct.