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 produced.
We know that at standard temperature and pressure (S.T.P), 1 mole of any gas occupies 22.4 liters (or 22,400 mL).

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

\[ \text{Moles of } N_2 = \frac{\text{Volume of } N_2}{\text{Molar volume at S.T.P}} = \frac{56 \text{ mL}}{22400 \text{ mL/mol}} = \frac{56}{22400} = 0.0025 \text{ moles} \]

### Step 2: Calculate the mass of nitrogen in grams.
The molecular weight of nitrogen gas (N₂) is 28 g/mol (since the atomic weight of nitrogen is 14 g/mol and there are two nitrogen atoms in a molecule of nitrogen gas).

Now, we can calculate the mass of nitrogen:

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

### Step 3: Calculate the percentage of nitrogen in the organic compound.
To find the percentage of nitrogen in the compound, we use the formula:

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

Substituting the values we have:

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

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

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