Question

determine the molecular formula for a compound that contains 22.5% Na, 30.4% P, and 47.1% O and a molar mass of 306 g/mol

Answer 1

Mr Na = 0.225 • 306 = 69 g/mol

Mr P = 0.304 • 306 = 93 g/mol

Mr O = 0.471 • 306 = 144 g/mol

coef. Na = 69/23 = 3

coef. P = 93/31 = 3

coef. O = 144/16 = 9

Molecular Formula : Na3P3O9