1.
Fe + 2HCl --->FeCl2+H2 mdHCl=182,5*10/100=18,25 g
2*36,5g 1mol
18,25g x=0,25 moli H2
2. 500g sol. 10% H2SO4
md=500*10/100=50 g m H2O=500g-50g=450g
masa de H din 50g H2SO4 este
98g H2SO4...........2gH
50g........................x=1,02g H
masa de H din 450 g apa
18g............2gH
450g...............y=50g H in total m H=1,02g+50g=51,02g H si 25,51 moli H2