What is the empirical formula of a substance that is 53.5% C, 15.5% H, 31.1% N?

For each carbon, hydrogen and nitrogen. You have to divide each percentage by its atomic mass.

C = 53.5/12.0107 = 4.45436

H = 15.5/1.00794 = 15.377899

N = 31.1/14.0067 = 2.220365

Round the number to significant figures

C = 4.45

H = 15.4

N = 2.22

Divide Each Number by the smallest number out of the three

so N = 2.22/2.22 = 1

H = 15.4/2.22 = 6.9 = 7

C = 4.45/2.22 = 2

So the Formula Should Be C2H7N