2Al + 6HCl -> 2AlCl3 + 3H2
2 moli Al.................6 moli HCl
x=2 moli Al............6 moli HCl
6 moli HCl...................2 moli AlCl3...........3 moli H2
6 moli HCl..................x=2 moli................y=3 moli H2
H2 + 1/2O2 -> H2O
1 mol H2.................1 mol H2O
3 moli H2..................3 moli H2O
md = 2*133,5=267g
ms=3*18+267=321g sol.
C=md/ms*100=267/321*100 = 83,17757%
mH2O=3*18=54g
25=267/267+mH2O*100 => 25(267+mH2O)=267*100 -> 6675+25mH2O=26700 -> 20025=25mH2O => mH2O=801g
mH2O adaugat = 801-54=747g