Răspuns:
1. MCH4=12+4=16g/mol
n=64/4=16moli
2. MH2O =2×1+16=18g/moli
18gH2O..........2gH
54gH2O.........xg
x=54×2/18=6gH
3. MH2O =18g/mol
18gH2O.........16gO
48gH2O........ygO
y=48×16/48=6g
4.MH2O =18g/moli
m=5×18=90gH2O
