What is the empirical formula of a compound that contains 4.0 g of hydrogen and 28 g of nitrogen?

Step 1: Convert the mass of each element to moles.

4.0g H x 1mol H/1.00794g H = 4.0 moles H

28g N x 1mol N/14.0067g N = 2.0 moles N

Step 2: Divide each mole value by the smallest number of moles calculated.

H = 4.0 moles/2.0 moles = 2

N = 2.0 moles/2.0 moles = 1

Empirical Formula = NH2