1.2Na+2H2O=2NaOH+H2
2. 2NaOH+CuSO4=Cu(OH)2+Na2SO4
3. NaOH+HCl=NaCl+H2O
4. 2NaOH+CO2=Na2CO3+H2O
MNaOH=23+16+1=40
40 g...23.gNa...16gH....1gH
100 x y z
MCu(OH)2=64+2*16+2*1=98u.a.m
98 g..........64gCu......32gO.....2gH
100g ...............x...........y............z
x,y,z sunt procentele
