A compound with a percent composition by mass of 24.61% C, 2.75% H, and 72.64% Cl has a molar mass of 292.82 g/mol. What is the empirical formula of the compound

Question

Quizplus · Accepted Answer

To find the empirical formula, convert the percentages to grams (assuming 100 g total), then to moles: C: 24.61 g / 12.01 g/mol = 2.049 mol, H: 2.75 g / 1.008 g/mol = 2.727 mol, Cl: 72.64 g / 35.45 g/mol = 2.049 mol. Divide by the smallest number of moles (2.049) to get the ratio: C: 1, H: 1.33, Cl: 1. Multiply by 3 to get whole numbers: C: 3, H: 4, Cl: 3. Thus, the empirical formula is C₃H₄Cl₃.

A Compound with a Percent Composition by Mass of 24