A commercial farmer wants to select a synthetic fertilizer that delivers the maximum nitrogen content per unit mass of compound.
Which of the following nitrogen-containing compounds contains the greatest percentage by mass of nitrogen?
[Relative atomic masses, ArA_rAr: H=1.0\text{H} = 1.0H=1.0; C=12.0\text{C} = 12.0C=12.0; N=14.0\text{N} = 14.0N=14.0; O=16.0\text{O} = 16.0O=16.0; S=32.1\text{S} = 32.1S=32.1; K=39.1\text{K} = 39.1K=39.1]
Ammonium sulfate, (NH4)2SO4\text{(NH}_4\text{)}_2\text{SO}_4(NH4)2SO4
Urea, CO(NH2)2\text{CO(NH}_2\text{)}_2CO(NH2)2
Ammonium nitrate, NH4NO3\text{NH}_4\text{NO}_3NH4NO3
Potassium nitrate, KNO3\text{KNO}_3KNO3
199 exam-style questions on OCR A A Level Chemistry Atoms and reactions, covering Atomic structure and isotopes, Compounds, formulae and equations, Amount of substance, Acids, and Redox. Each one has a worked solution and a mark scheme showing where the marks go.