What is the empirical formula of a compound that contains 25.92 percent nitrogen and 74.07 percent oxygen?

N2 O5

Explanation!

When given %, assume you have 100 g of the substance. Find moles, divide by lowest count. In this case you'll end up with

25.92 g N 14.01 g N/mol N = 1.850 mol N

74.07 g O 16.00 g O/mol O = 4.629 mol O

The ratio between these is 2.502 mol O/mol N, which corresponds closely with N2 O5.