A compound is 44.7% P and the rest O. Determine its emperical formula.

P₅O₁₂

Explanation:

Assume that you have 100 g of the compound.

Then you have 44.7 g P and 55.3 g O.

1. Calculate the moles of each atom

Moles of P = 44.7 * 1/30.97 = 1.443 mol Al

Moles of O = 55.3 * 1/16.00 = 3.456 mol O

2. Calculate the molar ratios.

P: 1.443/1.443 = 1

O: 3.456/1.443 = 2.395

3. Multiply by a number to make the ratio close to an integer

P: 5 * 1 = 5

O: 5 * 2.395 = 11.97

3. Determine the empirical formula

Round off all numbers to the closest integer.

P: 5

O: 12

The empirical formula is P₅O₁₂.