Răspuns:
III.
1. 2Mg + O2 → 2Mgo
2. C+ 2H2 → CH4
3. CuCO3 → CuO +CO2↑
4.2Al +3Cl2 → 2AlCl3
5. 2H2O → 2H2↑ +O2↑
IV.
2H2 + O2 →2H2O
2Ca + O2 → 2CaO
CaO + H2O→ Ca(OH)2
compozitia procentuala
MCa(OH)2=40+2x16+2x1=74g/mol
74gCa(OH)2....................40gCa.............32gO...........2gH
100gCa(OH02.................x%Ca................y%O............zg%
x=100x40/74=calculeaza
y=100x32/74=calculeaza
z=100x2/74=calculeaza
Explicație:
