Nitrogen analysis comparison: Among the listed fertilisers, which contains the maximum percentage of nitrogen by mass under standard specifications?

Introduction / Context:
Different nitrogen fertilisers supply widely varying percentages of nitrogen, influencing transport, storage, and field application economics. Recognising which has the highest N% helps in quick selection and troubleshooting dosing errors.

Given Data / Assumptions:

• Typical grades: urea ≈ 46% N; ammonium nitrate ≈ 33–35% N; ammonium sulphate ≈ 21% N; CAN ≈ 26–28% N.
• Anhydrous (liquid) ammonia contains about 82% N by mass.
• Nominal values are used for comparison.

Concept / Approach:
Anhydrous ammonia (NH3) is essentially nitrogen-rich, containing ~14/17 by mass ≈ 82% N. No other common solid nitrogen fertiliser exceeds this percentage. Urea at 46% N is the highest among typical solids but still far below anhydrous ammonia. Therefore, among the options provided, liquid ammonia has the maximum nitrogen content.

Step-by-Step Solution:

Verification / Alternative check:
Specification sheets and fertiliser handbooks confirm the above typical analyses.

Why Other Options Are Wrong:

• Urea: highest solid N %, but less than ammonia.
• Ammonium nitrate/CAN/ammonium sulphate: significantly lower N contents.

Common Pitfalls:
Confusing volumetric concentration with mass percentage; forgetting ammonia’s very high N fraction due to its small molecular mass.

Final Answer:
Liquid ammonia