Question

There are $3$ samples of hydrogen peroxide labelled $10$ vol., $15$ vol and $20$ vol. Half litre of each was mixed. Calculate volume strength of the new solution.

• A. 7.5
• B. 15.0
• C. 22.5
• D. 51.0

Answer 1

Answer: (B)

Normality $=\frac{\text { Volumestrength }}{5.6}$

$N_{1}=\frac{10}{5.6}, N_{2}=\frac{15}{5.6}, N_{3}=\frac{20}{5.6}$

New normality $=\frac{N_{1} V_{1}+N_{2} V_{2}+N_{3} V_{3}}{V_{1}+V_{2}+V_{3}}$

$N=\frac{\left(\frac{10}{5.6} \times 0.5\right)+\left(\frac{15}{5.6} \times 0.5\right)+\left(\frac{20}{5.6} \times 0.5\right)}{0.5+0.5+0.5}$

On solving, $N=\frac{15}{5.6}$

New volume strength $=N \times 5.6=\frac{15}{5.6} \times 5.6=15$ vol