How many hydrogen atoms are in 8.80 mol of ammonium sulfide

Assuming that the ammonium sulfide formula is (NH4) 2S then you can see that there are 2 nitrogen, 8 hydrogen and 2 sulfur atoms for every ammonium sulfide. If the amount of ammonium sulfide is 8.9 moles, then the number of hydrogen atoms should be: 8/1 * 8.9 mol = 71.2 moles