Determine the empirical formula of the following compound if a sample contains 0.104 molK, 0.052 molC, and 0.156 molO.

The empirical formula is K₂CO₃.

The empirical formula is the simplest whole-number ratio of atoms in a compound.

The ratio of atoms is the same as the ratio of moles, so our job is to calculate the molar ratio of K:C:O.

I like to summarize the calculations in a table.

Element Moles Ratio¹ Integers²

K 0.104 2.00 2

C 0.052 1.00 1

O 0.156 3.00 3

¹ To get the molar ratio, you divide each number of moles by the smallest number.

² Round off the number in the ratio to integers to integers (2, 1, and 3).

The empirical formula is K₂CO₃.