calculez moli H2
n(niu)= V/V,m=> n=5,6l/22,4l/mol= 0,25molH2
2mol.............................1mol
2HCl + Zn ---> ZnCl2 + H2
x.....................................0,25mol
x= 0,50mol HCl
m= nxM----> m,HCl= 0,5molx 36,5g/mol=18,25gHCl= md
c= mdx100/ms
20/100= 18,25/ms---> ms=91,25g sol.HCl
volumul de solutie se calculeaza din densitate si m
ro-==m/v; 0,098g/ml= 91,25g/ V........................calculeaza ,dar verifica unitatea de masura a densitatii solutiei