Module 2-Empirical Formula/water of crystallisation

Question 1

How do you work out empirical formula

Answer 1

1) work out number of moles using Mr and the mass given (use 100g if it’s a %)
2) divide all the values of number of moles by the smallest number
3) turn into whole number ratios

Question 2

How do you work out the link between empirical formula and RMM?? To find actual molecular formula

Answer 2

Divide the RMM of the question by the RMM of the empirical formula- it will tell you what to multiply the empirical formula by to get the molecule formula