Question

Two compounds of hydrogen and oxygen are tested. Compound I contains 15.0 g of hydrogen and 120.0 g of oxygen. Compound II contains 2.0 g of hydrogen and 32.0 g of oxygen. How does this problem illustrate the Law of Multiple Proportions?

Answer 1

compound I :

mass of hydrogen = 15.0 g

mass of oxygen = 120.0 g

total mass = 120 + 15 = 135 g

mass % of H = (15 / 135 ) x 100 = 11.1 %

mass % of H = 11.1 %

mass % of O = (120 / 135) x 100 = 88.9 %

mass % of O = 88.9 %

compound II :

mass of hydrogen = 2.0 g

mass of oxygen = 32.0 g

total mass = 34 g

mass % of H = (2 / 34 ) x 100 = 5.88

mass % of H = 5.88 %

mass % of O = 94.12 %

ratio :

Hydrogen in (compound 1 / compound 2 )

                = 0.1248 / 0.06247

(compound 1 / compound 2 ) = 2