MgO
M=24+16=40------->1mol=40g
Se calculeaza cantitatea de oxigen continuta in 24 g MgO
40g MgO-----------16 g O
24 g MgO----------Xg O
X=24.16:40= 9,6 g O
Trebuie calculata cantit. de H2O care va contine 9,6 g O.
MH2O=2+16=18--------->1mol=18g
18 g H2O---------16 gO
Yg H2O----------9,6 g O
Y=18.9,6:16= 10,8 g O
