Moles of ammonium sulfide = 5.80 mol
The formula of ammonium sulfide is (NH₄)₂S
So each molecule of ammonium sulfide has (4 x 2) or 8 atoms of H
One mole of ammonium sulfide has 8 moles of H
5.80 mol of ammonium sulfide has (8 x 5.8) or 46.4 moles of H
As per the definition of Avogadro's number, 1 mole = 6.022 x 10²³ atoms
46.4 moles of H x (6.022 x 10²³ atoms/ 1 mole of H)
= 2.8 x 10²⁵ H atoms
Therefore, 2.8 x 10²⁵ H atoms are in 5.80 mol of ammonium sulfide.