Active mass of 56g of `N_2` contained in 2 ltr. flask is

Options

A. 16 Mole. `lit^(-1)`
B. 32 Mole. `lit^(-1)`
C. 1.00 Mole. `lit^(-1)`
D. 0.1 Mole. `lit^(-1)`

Answer

To find the active mass of 56g of \( N_2 \) contained in a 2-liter flask, we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Molar Mass of \( N_2 \)**:
- The molar mass of nitrogen (N) is 14 g/mol.
- Since \( N_2 \) consists of two nitrogen atoms, the molar mass of \( N_2 \) is:
\[ \text{Molar mass of } N_2 = 14 \, \text{g/mol} \times 2 = 28 \, \text{g/mol} \]

2. **Calculate the Number of Moles of \( N_2 \)**:
- The formula to calculate the number of moles (n) is given by:
\[ n = \frac{\text{Given weight}}{\text{Molar mass}} \]
- Here, the given weight of \( N_2 \) is 56 g. Therefore:
\[ n = \frac{56 \, \text{g}}{28 \, \text{g/mol}} = 2 \, \text{moles} \]

3. **Determine the Volume of the Flask**:
- The volume of the flask is given as 2 liters.

4. **Calculate the Active Mass (Concentration)**:
- Active mass is defined in terms of molarity (M), which is the number of moles of solute per liter of solution:
\[ \text{Active mass (M)} = \frac{\text{Number of moles}}{\text{Volume in liters}} \]
- Substituting the values we have:
\[ \text{Active mass} = \frac{2 \, \text{moles}}{2 \, \text{liters}} = 1 \, \text{mol/L} \]

### Final Answer:
The active mass of 56g of \( N_2 \) contained in a 2-liter flask is **1 mol/L**.

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