Question

What is the number of grams of Hydrogen in 5.45 x 10^22 molecules NH3?

Answer 1

moles NH3 = 5.45 x 10^22/6.022 x 10^23 = ?? NH3.
moles H = 3x that number since there are three H atoms in one molecule of NH3.

g H = mols H x atomic mass H

Answer 2

0.274g H