To determine the percentage of nitrogen in the organic compound, we can follow these steps:
### Step 1: Calculate the effective pressure of nitrogen gas
The total pressure of the gas collected is given as 755.8 mm Hg, and we need to subtract the aqueous tension of water at 25°C, which is 23.8 mm Hg.
\[
\text{Effective Pressure (P1)} = \text{Total Pressure} - \text{Aqueous Tension} = 755.8 \, \text{mm Hg} - 23.8 \, \text{mm Hg} = 732 \, \text{mm Hg}
\]
### Step 2: Convert the temperature to Kelvin
The temperature is given as 25°C. To convert this to Kelvin:
\[
\text{Temperature (T1)} = 25 + 273 = 298 \, \text{K}
\]
### Step 3: Use the Ideal Gas Law to find the volume at NTP
At Normal Temperature and Pressure (NTP), the pressure (P2) is 760 mm Hg and the temperature (T2) is 273 K. We can use the formula derived from the Ideal Gas Law:
\[
\frac{P1 \cdot V1}{T1} = \frac{P2 \cdot V2}{T2}
\]
Rearranging to find \( V2 \):
\[
V2 = \frac{P1 \cdot V1 \cdot T2}{P2 \cdot T1}
\]
Substituting the values:
\[
V2 = \frac{732 \, \text{mm Hg} \cdot 31.7 \, \text{mL} \cdot 273 \, \text{K}}{760 \, \text{mm Hg} \cdot 298 \, \text{K}}
\]
Calculating \( V2 \):
\[
V2 \approx \frac{732 \cdot 31.7 \cdot 273}{760 \cdot 298} \approx 27.97 \, \text{mL}
\]
### Step 4: Calculate the moles of nitrogen gas
The molar volume of an ideal gas at NTP is 22400 mL. The number of moles of nitrogen gas (N2) can be calculated using the formula:
\[
\text{Moles of N2} = \frac{V2}{22400}
\]
Substituting the value of \( V2 \):
\[
\text{Moles of N2} = \frac{27.97 \, \text{mL}}{22400 \, \text{mL/mol}} \approx 0.00125 \, \text{mol}
\]
### Step 5: Calculate the mass of nitrogen
The molar mass of nitrogen (N2) is approximately 28 g/mol. Thus, the mass of nitrogen can be calculated as:
\[
\text{Mass of N2} = \text{Moles of N2} \times \text{Molar Mass of N2} = 0.00125 \, \text{mol} \times 28 \, \text{g/mol} \approx 0.035 \, \text{g}
\]
### Step 6: Calculate the percentage of nitrogen in the organic compound
Finally, the percentage of nitrogen in the organic compound can be calculated using the formula:
\[
\text{Percentage of N} = \left( \frac{\text{Mass of N2}}{\text{Mass of Organic Compound}} \right) \times 100
\]
Substituting the values:
\[
\text{Percentage of N} = \left( \frac{0.035 \, \text{g}}{0.2325 \, \text{g}} \right) \times 100 \approx 15.06\%
\]
### Final Answer:
The percentage of nitrogen in the organic compound is approximately **15.1%**.
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