MgSO4
Se calculeaza masa moleculara MMgSO4=24+32+4.16=120
Daca in 120 g MgSO4 se afla 24 g Mg ,32 g S,64 g O2, atunci in 100 g MgSO4 se afla x,y,z
120gMgSO4-----------24g Mg--------32gS-------64 g O2
100 g MgSO4----------X-----------------Y------------Z
X=100.24:120=20 la suta Mg
y=100.32:120=26,6 la suta S
Z=100.64:120=53,3 la suta O2
