Percent Composition Chemistry Example 2

Follow the full solution, then compare it with the other examples linked below.

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Calculate the percent by mass of nitrogen in ammonium nitrate (

\text{NH}_4\text{NO}_3

1
Molar mass: $2(14.01) + 4(1.008) + 3(16.00) = 28.02 + 4.032 + 48.00 = 80.05\,\text{g/mol}$ .
2
Total nitrogen mass per formula unit: $2 \times 14.01 = 28.02\,\text{g}$ .
3
%N $= \frac{28.02}{80.05} \times 100\% = 35.00\%$ .

Answer

35.00\%\text{ nitrogen}

Ammonium nitrate's high nitrogen content makes it valuable as a fertilizer. Note there are two nitrogen atoms per formula unit — one in

\text{NH}_4^+

and one in

\text{NO}_3^-

About Percent Composition

Percent composition is the percentage by mass of each element in a chemical compound.

Calculate the percent composition by mass of each element in [formula].

What is the percent composition of carbon in [formula]? (C = 12.01, O = 16.00)

What percent by mass of calcium carbonate ([formula]) is oxygen? (Ca = [formula], C = [formula], O =