Răspuns:
Explicație:
M Ca = 40 g/mol
M H20 = 18 g/mol
M H = 1 g/mol
M CaSO4.2H2O = 40 + 32 + 16*4 + 2*18 = 172 g/mol
172 g ..................40 g Ca................36 g H2O..................4 g hidrogen
100....................x....................................y...............................z
x = 100*40/172 = 23,26%
y = 100*36/172 = 20,93%
z = 100*4/172 = 2,33%