Question

What is the empirical formula of a compound containing 83% potassium and 17% oxygen?

Answer 1

`K_2O`,

Explanation:

The following method serves for every compound:

In each 100 g of the compound you have 83 g of potassium and 17 g of oxygen.

To determine the empiriacal formula you have to pass these masses into mols

`83/39.1=2.12 mol K` and `17/16=1.06 mol O`

Now divide all the numbers by the smallest you have obatined:

`2.12/1.06=2.0 K` and `1.06/1.06=1 mol O`

So it is `K_2O`

At this stage you can have numbers that are not integer. In this case you would have to multiply the resulsts by an integer in a way the final result is a proportion of integers:

Imagine you had obtained 1.5 K for 1 O. You just had to multiply by 2 to get the integer proportion of 3:1.