Question

The volume of oxygen liberated from 15 ml of 20 volume ${H_2}{O_2}$ is:
A. 250 ml
B. 300 ml
C. 150 ml
D. 200 ml

Answer 1

We know that the hydrogen peroxide is a thermodynamically unstable molecule and decomposes to form water and oxygen and it is a spontaneous process. The volume of oxygen liberated at STP is given by the formula:
${\text{volume of }}{{\text{O}}_2}{\text{ liberated = volume strength of }}{H_2}{O_2} \times {\text{volume of }}{H_2}{O_2}$

Complete step by step answer:
- We know that at constant temperature and pressure, the volume of oxygen liberated by the decomposition of hydrogen peroxide is given by:
${\text{volume of }}{{\text{O}}_2}{\text{ liberated = volume strength of }}{H_2}{O_2} \times {\text{volume of }}{H_2}{O_2}$
- In the question, it is given that volume strength of ${H_2}{O_2}$ is 20 and the total volume of ${H_2}{O_2}$ is 15 ml. By substituting these values in the equation, we get:
Volume of oxygen liberated = $20 \times 15 = 300$ ml.
So the correct answer is “B”:

Additional Information: Hydrogen peroxide has so many uses in our daily life. Hydrogen peroxide is used as a disinfectant and used in certain waste water treatment processes to remove some organic impurities. Hydrogen peroxide can be used for sterilization of various surfaces including the tools used in surgery and used in the form of vapour for the room sterilization. Hydrogen peroxide can be used as an environmentally safe alternative for chlorine based bleaches. It is recognised as a safe anti-microbial agent by the US Food and Drug Administration.

Note: We know that hydrogen peroxide is thermodynamically least stable and it will decompose slowly in the presence of light. To avoid this decomposition due to its instability, hydrogen peroxide is stored with a stabilizer in a weakly acidic solution in a dark coloured bottle.