Question

The volume of oxygen liberated at STP from $15\text{mL}$ of $20$ volume $H_2{O}_2$ is:

• A. $250\text{mL}$
• B. $300\text{mL}$
• C. $150\text{mL}$
• D. $200\text{mL}$

Answer 1

The correct option is B $300\text{mL}$

1 $L$ of 20 volume of $H_2{O}_2$ will give 20 $L$ of oxygen at NTP.

Oxygen liberated from 1000 $mL$ $(1L$) of $H_2{O}_2$ = 20 $L$

$\therefore$ Oxygen liberated from 15 $mL$ of $H_2{O}_2$ = $\frac{20}{1000}\times 15$ = $0.3L$ = $300mL$