Calculation of Percent Composition

Analysis of a 12.04-g sample of a liquid compound composed of carbon, hydrogen, and nitrogen showed it to contain 7.34 g C, 1.85 g H, and 2.85 g N. What is the percent composition of this compound?

C: 61.0%, H: 15.3%, N: 23.7%

Explanation:

We can calculate the percent by mass of each element using the following expression.

%Element = (mass of the element/mass of the compound) * 100%

Carbon

%C = (7.34 g/12.04 g) * 100% = 61.0%

Hydrogen

%H = (1.85 g/12.04 g) * 100% = 15.3%

Nitrogen

%N = (2.85 g/12.04 g) * 100% = 23.7%

The percent composition of this compound is C: 61.0%, H: 15.3%, N: 23.7%.