Relative Formula Mass (Mr):

1. Find mass number of each element in the equation

2. Multiply the mass number by the little number next to the element

3. Add them

Empirical Formula:

Smallest whole number ratio of atoms in a compound.

1. Divide the little numbers by the HCF e.g:

C6H12O6

Divide all by 6 and it becomes CH2O

• Moles = mass/Mr

• To work out ratio, divide both of the moles by the smallest mole out of the set

Balancing Equations using Masses:

1. Find moles

2. However many moles you have is the number you put in front of the element/compound to balance the equation