Q9 / 160 · TS EAMCET 2020 (10 Sep Shift 1) · Chemistry
What is the \% strength of 22.4 volume of $\mathrm{H}_2 \mathrm{O}_2$ solution?
- A$3.4 \%$
- B$2.5 \%$
- C$5 \%$
- Correct answerD$6.8 \%$
Solution
$22.4 \mathrm{vol} \mathrm{H} \mathrm{O}_2$ means $\mathrm{l} \mathrm{mL}$ of $\mathrm{H}_2 \mathrm{O}_2$ solution gives $22.4 \mathrm{~mL} \mathrm{O}_2$.
$\begin{array}{ll}
2 \mathrm{H}_2 \mathrm{O}_2 & \longrightarrow 2 \mathrm{H}_2 \mathrm{O}+\mathrm{O}_2 \\
2 \mathrm{~mol} & 1 \mathrm{~mol} \\
68 \mathrm{~g} & 22400 \mathrm{~mL} \text { at NTP }
\end{array}$
$\therefore 22400 \mathrm{~mL} \mathrm{O}_2$ is obtained by $68 \mathrm{~g} \mathrm{H}_2 \mathrm{O}_2$
$\therefore 22.4 \mathrm{~mL} \mathrm{O}_2$ is obtained by
$\frac{68 \times 22.4}{22400}=0.068 \mathrm{~g} \mathrm{H}_2 \mathrm{O}_2$
or $1 \mathrm{~mL} \mathrm{H}_2 \mathrm{O}_2$ solution $=0.068 \mathrm{~g}$
$\therefore 100 \mathrm{~mL} \mathrm{H}_2 \mathrm{O}_2$ solution $=0.0680 \times 100=6.8 \%$
Hence, the correct answer is option: 'D'.