Meaning of 5.6 volume hydrogen peroxide

A solution labeled as $5.6$ volume means:

• $1$ volume of solution gives $5.6$ volumes of $O_2$ at STP on decomposition.

Decomposition reaction: $2H_2O_2 \rightarrow 2H_2O + O_2$

Take 1 L of solution

Then volume of $O_2$ liberated at STP $= 5.6$ L.

Moles of $O_2$ produced: $n(O_2)=\frac{5.6}{22.4}=0.25 \text{ mol}$

Find moles of $H_2O_2$ required

From the reaction: $2 \text{ mol } H_2O_2 \text{ produce } 1 \text{ mol } O_2$

Therefore, moles of $H_2O_2$ in 1 L solution: $n(H_2O_2)=2 \times 0.25=0.5 \text{ mol}$

Molarity

Since $1$ L of solution contains $0.5$ mol of $H_2O_2$, $M=0.5$

Mass of $H_2O_2$ in 1 L solution

$m = n \times M_m = 0.5 \times 34 = 17 \text{ g}$

Mass of 1 L solution

Density $=1$ g/mL, so mass of $1000$ mL solution is: $1000 \text{ g}$

Mass percentage

$\%\, by\, mass = \frac{17}{1000} \times 100 = 1.7\%$

Match with options

• Mass percentage $= 1.7$
• Molarity $= 0.5$

Hence the correct option is D.

Comparison with stored answer

Stored correct answer: D

Derived answer: D

They agree.