# A compound with the empirical formula CH2 has a molar mass of 28 g/mol. What is the molecular formula for this compound?

Nov 28, 2015

The molecular formula is $\text{C"_2"H"_4}$.

#### Explanation:

Determine the empirical formula mass.

$\text{CH"_2} :$(1xx12"g/mol")+(2xx1"g/mol")="14 g/mol"

Divide the molecular mass by the empirical formula mass.

$\left(28 \cancel{\text{g/mol")/(14cancel"g/mol}}\right) = 2$

Multiply the subscripts in the empirical formula times $2$.

The molecular formula is $\text{C"_2"H"_4}$.