A 65.2 g sample of a compound contains 32.1 g of phosphorus and the rest is oxygen.What is the empirical formula of the compound? A)P₃O₂ B)PO₂ C)PO D)P₂O₃

Question

Quizplus · Accepted Answer

To find the empirical formula, we need to first determine the moles of each element in the compound.

Moles of phosphorus = 32.1 g / 31.0 g/mol = 1.036 mole
Moles of oxygen = (65.2 g - 32.1 g) / 16.0 g/mol = 1.994 mole

Next, we divide each number of moles by the smallest number to get a simple whole number ratio:

Phosphorus: 1.036 / 1.036 = 1
Oxygen: 1.994 / 1.036 = 1.92 or approximately 2

So the empirical formula is PO2, but we need to simplify it by dividing both subscripts by the greatest common factor, which is 2. This gives us the empirical formula of PO.

A 652 G Sample of a Compound Contains 32