K2O
raport atomic=r.a=2K:O=2:1
raport de masa=r.m.=2AK:AO=2.39:16=78:16=39:8
(se simplifica cu 2)
Compozitie procetuala prin masa moleculara
M=2.39+16=94 94 g K20 reprezinta 1MOL K2O
94 g K2O-----------78gK-----------16 g O
100 g K2O----------X-----------------Y
X=100.78:94=82,97 la suta K
Y=100.16:94=17,02 la suta O