Question

A compound contains 47.08% carbon, 6.59% hydrogen and 46.33% chlorine by mass. what is the empirical formula for the compound.

Answer 1

Assume there is 100 grams of the compound. The amounts of each elements would be: 47.08 g C, 6.59 g H and 46.33 g Cl. Convert them to moles.

mol C: 47.08 g * 1 mol/12 g = 3.9233
mol H: 6.59 g * 1mol/1g = 6.59
mol Cl: 46.33 g * 1mol/35.45 g = 1.3069

Divide the smallest amount of moles to each moles of the elements:
C: 3.9233/1.3069 = 3
H: 6.59/1.3069 = 5
Cl: 1.3069/1.3069 = 1

Therefore, the empirical formula of the compound is C₃H₅Cl.