To calculate the volume strength of a 2 normal (2N) solution of hydrogen peroxide (H₂O₂), we will follow these steps:
### Step 1: Understand the relationship between Normality and Strength
Normality (N) is defined as the number of equivalents of solute per liter of solution. The strength of a solution can be calculated using the formula:
\[ \text{Strength} = \text{Normality} \times \text{Equivalent Weight} \]
### Step 2: Calculate the Equivalent Weight of H₂O₂
The equivalent weight of a substance can be calculated using the formula:
\[ \text{Equivalent Weight} = \frac{\text{Molecular Weight}}{\text{n-factor}} \]
For hydrogen peroxide (H₂O₂):
- The molecular weight (M) of H₂O₂ = 34 g/mol.
- The n-factor for H₂O₂ in this reaction (as it can release 1 mole of O₂) is 2.
Thus, the equivalent weight of H₂O₂ is:
\[ \text{Equivalent Weight} = \frac{34 \, \text{g/mol}}{2} = 17 \, \text{g/equiv} \]
### Step 3: Calculate the Strength of the H₂O₂ Solution
Now, using the normality and the equivalent weight, we can find the strength:
\[ \text{Strength} = 2 \, \text{N} \times 17 \, \text{g/equiv} = 34 \, \text{g/L} \]
### Step 4: Determine the Volume of O₂ produced
Next, we need to find out how much oxygen (O₂) is produced from this strength of H₂O₂. The reaction for the decomposition of H₂O₂ is:
\[ 2 \, \text{H₂O₂} \rightarrow 2 \, \text{H₂O} + \text{O₂} \]
From the stoichiometry of the reaction:
- 2 moles of H₂O₂ produce 1 mole of O₂.
### Step 5: Calculate the volume of O₂ produced at STP
At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22,400 mL.
From the strength calculated:
- 34 g of H₂O₂ corresponds to 1 mole (since 34 g is the molar mass).
- Therefore, 1 mole of H₂O₂ will produce \( \frac{1}{2} \) mole of O₂:
\[ \text{Volume of O₂} = \frac{1}{2} \times 22,400 \, \text{mL} = 11,200 \, \text{mL} \]
### Step 6: Calculate the Volume Strength
Since 34 g of H₂O₂ produces 11,200 mL of O₂, we can find the volume strength:
- The volume strength is defined as the volume of O₂ produced by 1 mL of H₂O₂ solution.
- Therefore, for 1 L (1000 mL) of H₂O₂ solution:
\[ \text{Volume Strength} = \frac{11,200 \, \text{mL}}{1000 \, \text{mL}} = 11.2 \]
### Final Answer
The volume strength of the 2N H₂O₂ solution is **11.2**.
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