Calculate the percentage composition of each element in calcium hydroxide

54.1 % Ca, 43.2 % O, 2.7% H

Explanation:

Molecular formula for calcium hydroxide is Ca (OH) ₂

As we don't have a mass of Ca (OH) ₂ to find out the percentage composition, we consider that the question refers to 1 mol of compound.

1 mol of hydroxide weighs 74.08 g

1 mol of hydroxide has 1 mol of Ca, therefore 40.08 g are Ca

2 moles of O therefore 32g are O

2 moles of H therefore 2 g are H

Percentage composition is known as (Mass of element/Total mass). 100

(40.08 / 74.08). 100 = 54.1 % (32 / 74.08). 100 = 43.2 % (2 / 74.08). 100 = 2.7%