Empirical Formulae - the simplest whole number ratio of atoms of each element present in a compound
To work out the Empirical formulae split the answer up into 4 parts:
First work out the moles, by doing Mass(or %)/Mr.
Then work out the ratio, by dividing all of the ratios by the smallest ratios. You then need to make all the ratios integers if they are not already, by timesing or dividing.
Nitram is an ammonium fertiliser: it is 35% nitrogen, 5% hydrogen and 60% oxygen. Calculate its empirical formular.
Nitrogen Hydrogen Oxygen
Mass 35 5 60
Mr 14 1 16
Moles 2.5 5 3.75
Ratio 1 2 1.5
Whole 2 4 3
number ratio (Final ratio needs to be in interger form)