0.365 g of an orgainc compound containing nitrogen gave 56 ml nitrogen at S.T.P. The percentage nitrogen in the given compound is

Options

A. 19.18
B. 38.36
C. 9.18
D. 29.18

Answer

To find the percentage of nitrogen in the given organic compound, we can follow these steps:

### Step 1: Calculate the number of moles of nitrogen gas (N2) produced.
We know that at standard temperature and pressure (STP), 1 mole of any gas occupies 22.4 liters (or 22400 mL).

Given that 56 mL of nitrogen gas was produced, we can calculate the number of moles of nitrogen gas:

\[ \text{Moles of } N_2 = \frac{\text{Volume of } N_2}{\text{Molar Volume at STP}} = \frac{56 \, \text{mL}}{22400 \, \text{mL/mol}} = 0.0025 \, \text{mol} \]

### Step 2: Calculate the mass of nitrogen in the sample.
The molar mass of nitrogen gas (N2) is 28 g/mol (since each nitrogen atom has a mass of approximately 14 g/mol).

Now, we can calculate the mass of nitrogen in the sample:

\[ \text{Mass of } N_2 = \text{Moles of } N_2 \times \text{Molar Mass of } N_2 = 0.0025 \, \text{mol} \times 28 \, \text{g/mol} = 0.07 \, \text{g} \]

### Step 3: Calculate the percentage of nitrogen in the organic compound.
The percentage of nitrogen in the compound can be calculated using the formula:

\[ \text{Percentage of Nitrogen} = \left( \frac{\text{Mass of } N_2}{\text{Mass of the compound}} \right) \times 100 \]

Substituting the values we have:

\[ \text{Percentage of Nitrogen} = \left( \frac{0.07 \, \text{g}}{0.365 \, \text{g}} \right) \times 100 \approx 19.18\% \]

### Conclusion
The percentage of nitrogen in the given organic compound is approximately **19.18%**.

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