The empirical formula of a compound is CH₂O it molecular weight is 90 calculate the molecular formula of the compound.

Empirical formula (CH₂O) weight = 12 + 2 + 16 = 30
molecular weight = 90
$\mathrm{n}=\frac{\text{ molecular weight }}{\text{ Empirical formula weight }}=\frac{90}{30}=3$
Molecular formula = n × empirical formula
$=3\times {\mathrm{CH}}_2\mathrm{O}={\mathrm{C}}_3{\mathrm{H}}_6{\mathrm{O}}_3$