---
title: "Two common agricultural nitrogen fertilizers are ammonium nitrate, \\(\\text{NH}_4\\text{NO}_3\\) (molar mass \\(\\approx 80.0\\text{ g/mol}\\)), and urea, \\(\\text{CO(NH}_2)_2\\) (molar mass \\(\\approx 60.0\\text{ g/mol}\\)). Which of the two substances has the greater percent nitrogen by mass, and why?"
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url: "https://nerd-notes.com/ubq/119975/"
date_modified: "2026-08-21T08:31:23+00:00"
---

# Two common agricultural nitrogen fertilizers are ammonium nitrate, \(\text{NH}_4\text{NO}_3\) (molar mass \(\approx 80.0\text{ g/mol}\)), and urea, \(\text{CO(NH}_2)_2\) (molar mass \(\approx 60.0\text{ g/mol}\)). Which of the two substances has the greater percent nitrogen by mass, and why?

Two common agricultural nitrogen fertilizers are ammonium nitrate, \(\text{NH}_4\text{NO}_3\) (molar mass \(\approx 80.0\text{ g/mol}\)), and urea, \(\text{CO(NH}_2)_2\) (molar mass \(\approx 60.0\text{ g/mol}\)). Which of the two substances has the greater percent nitrogen by mass, and why?

- **A.** \(\text{NH}_4\text{NO}_3\), because each mole of \(\text{NH}_4\text{NO}_3\) has a greater total molar mass than a mole of \(\text{CO(NH}_2)_2\).
- **B.** \(\text{NH}_4\text{NO}_3\), because each formula unit of \(\text{NH}_4\text{NO}_3\) contains two separate nitrogen-containing ions.
- **C.** \(\text{CO(NH}_2)_2\), because each molecule of \(\text{CO(NH}_2)_2\) contains more nitrogen atoms than a formula unit of \(\text{NH}_4\text{NO}_3\).
- **D.** \(\text{CO(NH}_2)_2\), because both compounds contain \(2\text{ mol of N}\) per mole of compound, but \(\text{CO(NH}_2)_2\) has a smaller molar mass.

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