-calculez masa de acid din solutie
c/100= md/ms
63/100= md/300----> md= 189g HNO3
-Calculez moli de acid din aceasta masa, stiind M(miu)=63g/molHNO3
n(niu)= 189g/ 63g/mol= 3mol HNO3
-Deduc din ecuatie, moli H2
2mol....................................1mol
Zn + 2HNO3-----> Zn(NO3)2 + H2
3mol....................................x= 3/2molH2
calculez volumul
V= n,molx22,4l/mol
V= 1,5molx 22.4l/mol=......................calculeaza !!!!!
