A : The molarity of 20 volume `H_(2)O_(2)` is 3.58 M.
R : Volume strengh `= 5.6 xx` M.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanantion of the assertion, then mark (2)
C. If assertion is true statements but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the problem, we need to analyze the given information about hydrogen peroxide (H₂O₂) and its molarity and volume strength.

### Step-by-Step Solution:

1. **Understanding Volume Strength**:
- The term "20 volume" means that 1 liter of H₂O₂ solution can produce 20 liters of oxygen gas (O₂) when decomposed.

2. **Decomposition Reaction**:
- The decomposition of hydrogen peroxide can be represented by the equation:
\[ 2 \text{H}_2\text{O}_2 \rightarrow 2 \text{H}_2\text{O} + \text{O}_2 \]
- From this equation, we see that 2 moles of H₂O₂ produce 1 mole of O₂.

3. **Calculating Moles of O₂ Produced**:
- Since 1 liter of H₂O₂ solution produces 20 liters of O₂, we can find the moles of O₂ produced:
- At standard temperature and pressure (STP), 1 mole of gas occupies 22.4 liters.
- Therefore, the number of moles of O₂ produced from 20 liters is:
\[ \text{Moles of O}_2 = \frac{20 \text{ L}}{22.4 \text{ L/mol}} \approx 0.893 \text{ moles} \]

4. **Using Stoichiometry to Find Moles of H₂O₂**:
- According to the stoichiometry of the reaction, 2 moles of H₂O₂ are needed to produce 1 mole of O₂. Thus, the moles of H₂O₂ required for 0.893 moles of O₂ is:
\[ \text{Moles of H}_2\text{O}_2 = 2 \times 0.893 \approx 1.786 \text{ moles} \]

5. **Calculating Mass of H₂O₂**:
- The molar mass of H₂O₂ is calculated as follows:
- H: 1 g/mol × 2 = 2 g/mol
- O: 16 g/mol × 2 = 32 g/mol
- Total = 2 + 32 = 34 g/mol
- Now, we can find the mass of H₂O₂ needed:
\[ \text{Mass of H}_2\text{O}_2 = \text{Moles} \times \text{Molar Mass} = 1.786 \text{ moles} \times 34 \text{ g/mol} \approx 60.68 \text{ g} \]

6. **Finding Molarity**:
- The molarity (M) of the solution is given as 3.58 M. This means there are 3.58 moles of H₂O₂ in 1 liter of solution.

7. **Calculating Volume Strength**:
- Volume strength (VS) can be calculated using the formula:
\[ \text{Volume Strength} = \text{Molarity} \times 22.4 \text{ L/mol} \]
- Therefore, substituting the values:
\[ \text{Volume Strength} = 3.58 \times 22.4 \approx 80.03 \text{ volume} \]

### Conclusion:
- The assertion is correct as the molarity of 20 volume H₂O₂ is indeed 3.58 M.
- The reason is incorrect as the calculated volume strength is approximately 80.03 volume, not 5.6 × M.