MgSO4
raport atomic 1Mg:1S:4O=1:1:4
AMg=24 AS=32 AO=16
raport de masa 24:32:4.16=24:32:64=6:8:16=3:4:8 ( se simplifica cu 4 apoi cu 2)
Compozitie procentuala
MMgSO4=24+32+64=120
120 gMgSO4--------24 g Mg-------32g S---------64 g O
100g-------------------x-----------------y-----------------z
x=100.24:120=20 la suta Mg
y=100.32:120=26,6 la suta S
Z=120.64:12064 la suta O