Meaning of volume strength

Volume strength of a $H_2O_2$ solution means:

Number of volumes of $O_2$ (at STP) liberated by 1 volume of the solution.

Decomposition reaction of hydrogen peroxide

$2H_2O_2 \rightarrow 2H_2O + O_2$

From the reaction:

• $2$ moles of $H_2O_2$ give $1$ mole of $O_2$

Given molarity

The solution is $8.9\,M$, so:

$1\text{ L solution contains } 8.9\text{ mol } H_2O_2$

Moles of oxygen produced from 1 L solution

Using stoichiometry:

$\text{moles of } O_2 = \frac{8.9}{2} = 4.45$

Volume of $O_2$ at $273\,K$ and $1\,atm$

Use ideal gas equation:

$V = \frac{nRT}{P}$

$V = \frac{(4.45)(0.0821)(273)}{1}$

First calculate:

$0.0821 \times 273 = 22.4133$

Then:

$V = 4.45 \times 22.4133 = 99.74\text{ L}$

Volume strength

Since this oxygen comes from 1 L of solution, volume strength is:

$99.74$

Rounded to nearest integer:

$\boxed{100}$

Comparison with stored answer

Stored correct answer = $100$

Our derived answer also is $100$, so they agree.