Hydrogen peroxide `(H_2 O_2)` was first prepared by Thenard by acidifying barium peroxide and removal of excess water by evaporation under reduced pressure. Its strength can be expressed as weigth percentage or as volume percentage . 25% solution by weight means 25 g of hydrogen peroxide are present in 100 g of solution and 25 volume of hydrogen peroxide means that 1 litre of this solution will give 25 L of oxygen at NTP.
Calculated the strength of 25 volume solution of `H_2 O_2` Round off answer into two digits

Explanation

To calculate the strength of a 25 volume solution of hydrogen peroxide (H₂O₂), we can follow these steps:

### Step 1: Understand the Concept of Volume Strength
The volume strength of a solution indicates how many liters of oxygen gas (O₂) can be produced from 1 liter of the solution at Normal Temperature and Pressure (NTP). A 25 volume solution means that 1 liter of this solution can produce 25 liters of O₂.

### Step 2: Use the Reaction of Hydrogen Peroxide
The decomposition of hydrogen peroxide can be represented by the following reaction:
\[ 2 \text{H}_2\text{O}_2 \rightarrow 2 \text{H}_2\text{O} + \text{O}_2 \]

From this reaction, we can see that 2 moles of H₂O₂ produce 1 mole of O₂.

### Step 3: Calculate the Molar Volume of Oxygen
At NTP, 1 mole of any gas occupies 22.4 liters. Therefore, the volume of oxygen produced from 1 mole of H₂O₂ can be calculated as:
- 1 mole of H₂O₂ produces 0.5 moles of O₂.
- Thus, 1 mole of H₂O₂ produces \(0.5 \times 22.4 \, \text{L} = 11.2 \, \text{L}\) of O₂.

### Step 4: Relate Volume of O₂ to Mass of H₂O₂
Since we have a 25 volume solution, we can determine how many grams of H₂O₂ are needed to produce 25 liters of O₂:
- From the previous calculation, we know that 1 mole of H₂O₂ produces 11.2 L of O₂.
- Therefore, to produce 25 L of O₂, we need:
\[ \text{Moles of H₂O₂} = \frac{25 \, \text{L}}{11.2 \, \text{L/mole}} \approx 2.232 \, \text{moles} \]

### Step 5: Calculate the Mass of H₂O₂
The molar mass of H₂O₂ is approximately 34 g/mol. Thus, the mass of H₂O₂ required is:
\[ \text{Mass of H₂O₂} = 2.232 \, \text{moles} \times 34 \, \text{g/mole} \approx 75.89 \, \text{g} \]

### Step 6: Conclusion
The strength of a 25 volume solution of hydrogen peroxide is approximately 75.89 grams.

### Final Answer
**The strength of a 25 volume solution of H₂O₂ is approximately 75.89 g.**

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