Question

How many '$mL$' of perhydrol is required to produce sufficient oxygen which can be used to completely convert $2L$ of $SO_2$ gas to $SO_3$ gas?

• A. 10 mL
• B. 5 mL
• C. 20 mL
• D. 30 mL

Answer 1

Answer: (A)

10 mL

Answer 2

Perhydrol means $30 \%$ solution of $H _{2} O _{2}$.
$H _{2} O _{2}$ decomposes as
$2 H _{2} O _{2} \rightarrow 2 H _{2} O + O _{2}$
Volume strength of $30 \% H _{2} O _{2}$ solution is $100$ that means $1 \,mL$ of this solution on decomposition gives $100 \,mL$ oxygen.

Since, $100 \,mL$ of oxygen is obtained by $=1\, mL$ of $H _{2} O _{2}$
$\therefore 1000\, mL$ of oxygen will be obtained by
$=\frac{1}{100} \times 1000\, mL$ of $H _{2} O _{2}$
$=10 \,mL$ of $H _{2} O _{2}$