# Question c8eb4

Mar 12, 2017

The formula is ${K}_{2} O$

#### Explanation:

To do empirical formula problems, follow these steps:

1. Convert the masses given into moles, by dividing each mass by the molar mass of that substance:

moles K = (32.9 g)/(39.1 g/"mol") = 0.8414 " mol"

moles O = (6.73 g)/(16.0 g/"mol") = 0.4206 " mol"#

1. Next find a simple whole-number ratio between these mole amounts. It usually helps to divide both numbers by the smaller.

K: $\frac{0.8414}{0.4206} = 2.00$

O: $\frac{0.4206}{0.4206} = 1.00$

1. 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 = ${K}_{2} O$