Question

What is the approximate percentage of ${{H}_{2}}{{O}_{2}}$ in a sample labelled as 10 vol?

• A. 0.1
• B. 0.09
• C. 0.03
• D. 0.01

Answer 1

Answer: (C)

0.03

Answer 2

: 1 litre of 10 volume ${{H}_{2}}{{O}_{2}}$ gives 10 litre of oxygen at NTP 1 litre of 10 volume of ${{H}_{2}}{{O}_{2}}$ gives $\frac{10}{22.4}$ mol of oxygen From the equation, $2{{H}_{2}}{{O}_{2}}\to 2{{H}_{2}}O+{{O}_{2}}$ mole of ${{O}_{2}}=2$ mole of ${{H}_{2}}{{O}_{2}}$ $\frac{10}{22.4}$ mol of $=\frac{2\times 10}{22.4}=0.893$ mole of ${{H}_{2}}{{O}_{2}}$ $\therefore$ Molarity of 10 vol sample of ${{H}_{2}}{{O}_{2}}=0.893$ Strength of ${{H}_{2}}{{O}_{2}}$ in 10 volume sample $=0.893\times 34=30.4\text{ }g/L=3.04\text{ }$ .