How many hydrogen atoms are in 3.90 mol of ammonium sulfide?

First, the number of ammonium sulfide molecules should be calculated:

N = NA × n,

where NA - the Avogadro number, n - number of moles.

N (ammonium sulfide) = 6.022 × 1023 × 8.5 mol = 51.187 × 1023.

The moelcular formula of ammonium sulfide is (NH4)2S. It means that each molecule contains 8 hydrogen atoms.

As a result, 8.5 mol of (NH4)2S contain:

51.187 × 1023 × 8 = 41 × 1024 hydrogen atoms.

41 × 1024 hydrogen atoms

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.