# What is the molecular formula of a compound that has a molecular mass of 42 and an empirical formula of CH_2?

Dec 21, 2015

The molecular formula is $\text{C"_3"H"_6}$.

#### Explanation:

The empirical formula mass of $\text{CH"_2}$ is 14 g/mol.

Divide the molecular mass by the empirical formula mass.

$\frac{42}{14} = 3$

Multiply the subscripts of the empirical formula times three to get the molecular formula.

The molecular formula is $\text{C"_3"H"_6}$.