Question

What is the empirical formula for a compound that is 29.44\% calcium, 23.55% sulfur, and 47.01% oxygen? This compound is a common ingredient in plaster

Answer 1

Empirical formula is CaSO₄.

Step-by-step explanation:

Given data:

Percentage of calcium =29.44%

Percentage of sulfur = 23.55%

Percentage of oxygen = 47.01%

Empirical formula = ?

Solution:

Number of gram atoms of Ca = 29.44 / 40 = 0.74

Number of gram atoms of S = 23.55 / 32 = 0.74

Number of gram atoms of O = 47.01 / 16 = 3

Atomic ratio:

Ca : S : O

0.74/0.74 : 0.74/0.74 : 3/0.74

1 : 1 : 4

Ca : S : O = 1 : 1 : 4

Empirical formula is CaSO₄.