Which Nitrogen Compound Has the Highest Nitrogen Content?

Subject : Chemistry

Question:

Which nitrogen compound listed contains the greatest percent composition by mass of nitrogen?

A. N₂O

B. NH₃

C. NH₄NO₃

D. HCN

E. CH₄N₂O

Expert Verified Solution:

To determine which nitrogen compound has the greatest percent composition by mass of nitrogen, we need to calculate the percentage of nitrogen in each compound. This is done by dividing the molar mass of nitrogen in the compound by the molar mass of the entire compound, then multiplying by 100.

N₂O (Nitrous Oxide)

• Nitrogen mass: 2 × 14 g/mol = 28 g/mol
• Molar mass: 28 g/mol (N) + 16 g/mol (O) = 44 g/mol
• % Nitrogen = (28/44) × 100 ≈ 63.64%

 

NH₃ (Ammonia)

• Nitrogen mass: 14 g/mol
• Molar mass: 14 g/mol (N) + 3 × 1 g/mol (H) = 17 g/mol
• % Nitrogen = (14/17) × 100 ≈ 82.35%

 

NH₄NO₃ (Ammonium Nitrate)

• Nitrogen mass: 2 × 14 g/mol = 28 g/mol
• Molar mass: 28 g/mol (N) + 4 g/mol (H) + 3 × 16 g/mol (O) = 80 g/mol
• % Nitrogen = (28/80) × 100 = 35%

 

HCN (Hydrogen Cyanide)

• Nitrogen mass: 14 g/mol
• Molar mass: 1 g/mol (H) + 12 g/mol (C) + 14 g/mol (N) = 27 g/mol
• % Nitrogen = (14/27) × 100 ≈ 51.85%

 

CH₄N₂O (Urea)

• Nitrogen mass: 2 × 14 g/mol = 28 g/mol
• Molar mass: 12 g/mol (C) + 4 g/mol (H) + 28 g/mol (N) + 16 g/mol (O) = 60 g/mol
• % Nitrogen = (28/60) × 100 ≈ 46.67%

 

Among the given options, NH₃ (Ammonia) has the greatest percent composition by mass of nitrogen at approximately 82.35%. Thus, the correct answer is B. NH₃.