AS Chemistry question

Empirical formula


Hello, can someone explain this ratio to me?
Element: C | H
Percentage: 83.7 | 16.3
Molecular mass: 12 | 1
Moles: 6.975 | 16.5
The empirical formula is C3H7 because the ratio is 3:7
Sorry i'm really bad at maths.

If you divide both values you got for your moles by the smallest value, you get 1:2.333

For empirical formulae, you want the smallest whole number values, so you need to get rid of that 0.333.

Hopefully, you'll recognise the 0.333 at 1/3, so it is easy to get rid of the 0.333, by multiplying both sides by 3.

Shazzam. Your answer.