If a sample of ammonium sulfate contains 1.75 grams of nitrogen [N] atoms, calculate the mass (in grams) it contains of sulfur atoms [S].

Answer 1

We have (NH4)2SO4 contg 1.75 g N atoms.
1.75 g N atoms = ? mols N atoms
That's mol = g/molar mass = 1.75/14 = approx 0.125.
There are 2 mol N atoms in 1 mo (NH4)2SO4; therefore, we must have 0.1235/2 = mols (NH4)2SO4 = approx 0.0625.
Since there is 1 mol S in 1 mol (NH4)2SO4 then we must have 0.0625 mols S. Then g = mols S x atomic mass S = ? grams.