On level Chemistry

Question

A compound contains 46.7% nitrogen and 53.3% oxygen. If the molecular mass of the compound is 60.0 g/mol, what is the molecular formula?

Answer 1

1. 46.7% = 46.7 g N
2. 53.3% = 53.3 g O

Both percentages add up to 100%.

46.7g N * 1 mol N/ 14.01g N = 3.33 mol N

53.3g O * 1 mol O/ 16 g O = 3.33 mol O

N/O = 3.33 mol N / 3.33 mol O = 1

Empirical Formula = NO

(N₁O₁) _x = (14.01 g/mol + 16 g/mol) * x = 60.0 g/mol = 30.01 g/mol * x, x ≈ 2

N₂O₂ is the molecular formula.