Determine the empirical formula of a compound containing 83% potassium and 17.0% oxygen.

Question

Quizplus · Accepted Answer

Assuming we have 100g of the compound, we have 83g of potassium and 17g of oxygen. 
To find the empirical formula, we need to convert these masses to moles.

Number of moles of potassium = 83g / 39.1 g/mol = 2.12 mol
Number of moles of oxygen = 17g / 16.0 g/mol = 1.06 mol

Next, we divide both mole values by the smaller mole value (which is 1.06) to get the mole ratio:

Potassium: 2.12 mol / 1.06 mol = 2
Oxygen: 1.06 mol / 1.06 mol = 1

Therefore, the empirical formula of the compound is KO.

Determine the Empirical Formula of a Compound Containing 83% Potassium