Question

How many ammonium ions and how many sulfate ions are present in an 0.280 mol sample of (NH4)2SO4?

How many atoms of N, H, S, and O are contained in this sample?

Answer 1

moles of (NH4)2SO4 = 0.280

moles of NH4+ = 0.280 x 2 = 0.560

moles of SO4-2 = 0.280

1) number of ammonium ions = 0.560 x 6.023 x 10^23

                                           = 3.37 x 10^23

2) number of sulfate ions = 1.69 x 10^23

3)

N atoms = 3.37 x 10^23

S atoms = 1.69 x 10^23

H atoms = 8 x 0.28 x 6.023 x 10^23 = 1.35 x 10^24

O atoms = 4 x 0.28 x 6.203 x 10^23 = 2.41 x 10^24