# How do you determine the empirical formula of a compound that has the following composition: 92.3 percent C and 7.7 percent H?

Nov 7, 2016

As with all these problems, we assume that there are $100 \cdot g$ of unknown compound........to give an empirical formula of $C H$.

#### Explanation:

And then we work out the molar composition.

Thus $\text{Moles of carbon}$ $=$ $\frac{92.3 \cdot g}{12.011 \cdot g \cdot m o {l}^{-} 1} = 7.68 \cdot m o l$.

And $\text{Moles of hydrogen}$ $=$ $\frac{7.7 \cdot g}{1.00794 \cdot g \cdot m o {l}^{-} 1} = 7.64 \cdot m o l$.

Clearly, there is $1 : 1$ molar equivalence with respect to $C : H$.

The molecular formula is a multiple of the empirical formula, but we have no handle on that here.