Massa dari zat 2 mol kalsium sulfat

massa= mr x mol
          = 136 x 2 + 272

n CaSO4 = 2 mol
Mr CaSO4
= Ar Ca + Ar S + 4xAr O
= 40 + 32 + 64
= 136

Massa
= n x Mr
= 2 x 136
= 172 gram