Question
What is the percentage by mass of nitrogen in different compounds?
Answers
GPT-4o mini
To determine the percentage by mass of nitrogen in various compounds, you need to know the molecular formula of each compound and the molar masses of the constituent elements. The percentage by mass of nitrogen can be calculated using the following formula:
\[
\text{Percentage by mass of nitrogen} = \left( \frac{\text{mass of nitrogen in the formula}}{\text{molar mass of the compound}} \right) \times 100
\]
Here are some examples for common nitrogen-containing compounds:
1. **Ammonia (NH₃)**
- Molar mass of N = 14.01 g/mol
- Molar mass of H = 1.01 g/mol
- Molar mass of NH₃ = 14.01 + (3 × 1.01) = 17.04 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{17.04} \right) \times 100 \approx 82.17\% \)
2. **Nitric Acid (HNO₃)**
- Molar mass of O = 16.00 g/mol
- Molar mass of HNO₃ = 1.01 + 14.01 + (3 × 16.00) = 63.01 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{63.01} \right) \times 100 \approx 22.24\% \)
3. **Urea (NH₂CONH₂)**
- Molar mass of C = 12.01 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of Urea = 14.01 + 12.01 + 16.00 + 14.01 = 60.03 g/mol
- Percentage by mass of N = \( \left( \frac{2 \times 14.01}{60.03} \right) \times 100 \approx 46.63\% \)
4. **Sodium Nitrate (NaNO₃)**
- Molar mass of Na = 22.99 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of NaNO₃ = 22.99 + 14.01 + (3 × 16.00) = 85.00 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{85.00} \right) \times 100 \approx 16.48\% \)
5. **Nitrates (e.g., Potassium Nitrate, KNO₃)**
- Molar mass of K = 39.10 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of KNO₃ = 39.10 + 14.01 + (3 × 16.00) = 101.11 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{101.11} \right) \times 100 \approx 13.85\% \)
These calculations give you a good overview of the varying percentage by mass of nitrogen in different compounds. You can apply the formula above to any nitrogen-containing compound you are interested in analyzing.
\[
\text{Percentage by mass of nitrogen} = \left( \frac{\text{mass of nitrogen in the formula}}{\text{molar mass of the compound}} \right) \times 100
\]
Here are some examples for common nitrogen-containing compounds:
1. **Ammonia (NH₃)**
- Molar mass of N = 14.01 g/mol
- Molar mass of H = 1.01 g/mol
- Molar mass of NH₃ = 14.01 + (3 × 1.01) = 17.04 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{17.04} \right) \times 100 \approx 82.17\% \)
2. **Nitric Acid (HNO₃)**
- Molar mass of O = 16.00 g/mol
- Molar mass of HNO₃ = 1.01 + 14.01 + (3 × 16.00) = 63.01 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{63.01} \right) \times 100 \approx 22.24\% \)
3. **Urea (NH₂CONH₂)**
- Molar mass of C = 12.01 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of Urea = 14.01 + 12.01 + 16.00 + 14.01 = 60.03 g/mol
- Percentage by mass of N = \( \left( \frac{2 \times 14.01}{60.03} \right) \times 100 \approx 46.63\% \)
4. **Sodium Nitrate (NaNO₃)**
- Molar mass of Na = 22.99 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of NaNO₃ = 22.99 + 14.01 + (3 × 16.00) = 85.00 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{85.00} \right) \times 100 \approx 16.48\% \)
5. **Nitrates (e.g., Potassium Nitrate, KNO₃)**
- Molar mass of K = 39.10 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of KNO₃ = 39.10 + 14.01 + (3 × 16.00) = 101.11 g/mol
- Percentage by mass of N = \( \left( \frac{14.01}{101.11} \right) \times 100 \approx 13.85\% \)
These calculations give you a good overview of the varying percentage by mass of nitrogen in different compounds. You can apply the formula above to any nitrogen-containing compound you are interested in analyzing.