CaCO3
r.a.=1Ca :1Ca :3O=1:1:3
r.m.=ACa :AC :3AO=40:12:3.16=40:12:48=10:3:12
Compozitie procentuala prin masa moleculara
M=40+12+48=100------>1mol=100g
1oog CaCO3--------40 g Ca--------12 g C---------48 g O
100g ---------------------x------------------y-----------------z
x=100.40:100=40 la suta Ca
y=100.12:100=12 la suta
z 100.48:100=48 la suta O