The formula is
To do empirical formula problems, follow these steps:
- Convert the masses given into moles, by dividing each mass by the molar mass of that substance:
moles K =
moles O =
- Next find a simple whole-number ratio between these mole amounts. It usually helps to divide both numbers by the smaller.
- Use the ratio find in step 2 to write a formula. In this case, we now know there are 2 moles of K for each 1 mole of O:
Empirical formula =