What is the empirical formula of a compound that contains 49.4% K,20.3% S,and 30.3% O by mass? A)KSO₂ B)KSO₃ C)K₂SO₄ D)K₂SO₃ E)KSO₄

Question

Quizplus · Accepted Answer

To find the empirical formula, we need to convert the percentages into moles. Assume a 100 g sample of the compound, which gives the following amounts of each element:

- 49.4 g K = 1.27 mol K 
- 20.3 g S = 0.64 mol S
- 30.3 g O = 1.89 mol O

Next, we need to divide each of these mole values by the smallest mole value to get the simplest, whole-number ratio of atoms in the compound. In this case, the smallest mole value is 0.64 mol S:

- K: 1.27 mol/0.64 mol = 1.98 or ~2 
- S: 0.64 mol/0.64 mol = 1 
- O: 1.89 mol/0.64 mol = 2.95 or ~3

So the empirical formula is K2SO3. This corresponds to answer choice D.

What Is the Empirical Formula of a Compound That Contains