Question

There are three samples of $H_2{O}_2$ labelled as $10\text{vol}$., 1$5\text{vol}$., and $20\text{vol}$. Half litre of each sample is mixed and then diluted with equal volumes of water. Calculate the volume strength of the resultant solution.

• A. $1.339$
• B. $7.5$
• C. $5.0$
• D. $2.68$

Answer 1

The correct option is B $7.5$

Volume strength of $H_2{O}_2$ ​= $5.6\times N$

$N$ of $10$ volume $H_2{O}_2$ ​= $\frac{10}{5.6}N$

$N$ of $15$ volume $H_2{O}_2$ ​= $\frac{15}{5.6}N$

$N$ of $20$ volume $H_2{O}_2$ ​= $\frac{20}{5.6}N$

Since half litre of each sample is mixed, the total volume becomes $1.5L$

This mixture is diluted to double its volume.
So, $1.5L\times 2=3L$ or $3000mL$

$N\times 3000=\frac{10}{5.6}\times 500+\frac{15}{5.6}\times 500+\frac{20}{5.6}\times 500$

$N$ of $H_2{O}_2$​ mixture = $1.339N$

Volume strength of $H_2{O}_2$​= $1.339\times 5.6=7.5$