100g xg yg
Ca + H2SO4 =CaSO4 +H2
40g 98g 2g
MH2SO4=2+32+4.16=98------->1mol=98g
x=100.98:40=245 g H2SO4 [ md pentru solutie ]
c=md.100: ms
ms=md.100: c
ms=245 .100: 40=612,5 g sol. H2SO4
y=100.2 :40=5g H2
r. moli=n =m:M MH2=2g------>1mol=2g
n=5:2 =2,5 moli H2