Question

The empirical formula of a compound is CH₂O. If its molecular mass is 180, then the molecular formula of the compound is ______. 

Options

• \[\ce{C6H12O6}\]

• \[\ce{C3H6O3}\]

• \[\ce{C5H10O5}\]

• \[\ce{C4H8O4}\]

Answer 1

The empirical formula of a compound is CH₂O. If its molecular mass is 180, then the molecular formula of the compound is \[\ce{C6H12O6}\].

Explanation:

Empirical formula mass = (12× 1) + (1 × 2) +(16 × 1) = 30g

Molecular mass = 180 g

n = `"Molecular mass"/"Empirical formula mass"`

= `180/30`

= 6

∴ Molecular formula = n × (Empirical formula)

= 1 × \[\ce{C2H5Br =C2H5Br}\]