What is the empirical formula of a compound composed of 30.5 g potassium (k) and 6.24 g oxygen (o)?

The empirical formula of the compound is K₂O.

Step 1. Calculate the moles of each element

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 to O.

Moles of K = 30.5 g K × (1 mol K/(39.10 g K) = 0.7801 mol K

Moles of O = 6.24 g O × (1 mol O/16.00 g O) = 0.3900 mol O

Step 2. Calculate the molar ratio of the elements

Divide each number by the smallest number of moles

Ni:F = 0.1552:0.3100 = 2.001:1 ≈ 2:1

Step 3: Write the empirical formula

EF = K₂O