An unknown compound has a percent composition of 52.10% potassium, 15.8% carbon, and 32.1% oxygen. The molar mass of the compound is 150.22 g/mol. What is the empirical formula and the molecular formula of this compound?

A. KCO and K2C2O3

B. K2C2O3 and K6C6O9

C. K2C2O3 and K2C2O3

D. K2C2O3 and K4C4O6

E. K2C2O3 and KCO1.5

To determine the empirical formula and the molecular formula of the compound, we assume a basis of the compound of 100 g. We do as follows:

Mass Moles

K 52.10 52.10/39.10 = 1.33 1.33/1.32 ≈ 1

C 15.8 15.8/12 = 1.32 1.32/1.32 ≈ 1

O 32.1 32.1 / 16 = 2.01 2.01/1.32 ≈ 1.5

The empirical formula would most likely be KCO.

The molecular formula would be K2C2O3.