Question

given the following data C =66.7% H =11.1% Calculate the empirical formula of the compund

Answer 1

First, we calculate the moles of each element taking the percentages as a mass:

$66,7g\text{ C}\cdot\frac{1\text{ mol C}}{12\text{ g C}}=5,56\text{ mol C}$$11,1\text{ g H}\cdot\frac{1\text{ mol H}}{1\text{ g H}}=11,1\text{ mol H}$

We divided the number of moles by the smaller number of moles. In this case, C is the smallest:

$5,56\text{ mol C/5,56 =1}$$11,1\text{ mol H/5,56=1,99}\approx2$

These numbers give us the empirical formula wich is: CH2