22.
CO2 (dioxid de carbon)
raportul atomic 1:2
raportul de masa 12:32
23.
H2O
M H2O=1+1+16=18
H=2
O=16
18g...........2g H
100g..........x
x=2*100/18=11,11%
18g............16g O
100g...........y
y=16*100/18=88,89%
