Moles
Mole questions are really easy because you only have four key items to remember:
1) Moles are a number
2) Protons and neutrons weigh 1
6 x 1023 grams
3) How to work out the empirical formula of a compound
4) A mole of an ideal gas is always 24 litres
Once you understand these, it’s only the maths that’s difficult.
But mole questions are really easy.