M,Mg= 24g/mol
niu=m/M= 4,8g/24g/mol=0,2molMg
1mol.......2mol....................1mol
Mg + 2HCl----> MgCl2+ H2
0,2mol...x............................y
x=niu= 0,4molHCl---> m=niuxM=0,4molx36,5g/mol=.........calculeaza !!!
y= 0,2molH2---> V= niuxVm= 0,2molx22,4l/mol=...................calculeaza !!!!