A sample was decomposed in the laboratory and found to have 38.67g C, 16.22g H, and 45.11g N.?

Moles of C in the compound = 38.67 / 12 = 3.223 moles

moles of H = 16.22 / 1 = 16.22 moles

moles of N = 45.11 /14 = 3.223

molar ratios in the compound C:H:N = 3.223 :16.22: 3.223

divide by the smallest number 3.223 and we get 1:5:1

empirical formula is CH5N

empirical mass is ( 12+5+14) = 31 g

molar mass is 62.12 g so there are 2 empirical units in a mole of compound

molecular formula is C2H10N2

moles of compound in 3.50 g = 3.50 / 62.12 = 0.056342563 moles

there are 10 moles of H in a mole of the compound so we have 0.56342563 moles of H in the mass

so number of atoms = 6.02 *10 ^23 atoms / mol * 0.56342563 mole

= 3.392 *10^+23 atoms of H in the sample mass