[albert611]

Just did a lab about synthesizing alum [KAl(SO4)2·12H2O], but I don't understand how to write a balanced chemical equation for it. Heres a brief rundown of the procedure:

1. Add 25 mL 3M KOH to aluminum foil.
2. Acidify with 35 mL 3 M H2SO4.
3. Filter solution and boil.
4. Cool and allow crystals to form.

I tried balancing it with the equation that I got, but it didn't work. Thanks.

[AWK]

2Al + 2KOH + 6H₂O = 2K[Al(OH)₄ ] + 3H₂(g)

K[Al(OH)₄ ]  + 2H₂SO₄  + 2H₂O= K[Al(H₂O)₆ ](SO₄)₂

Note,  in solution and in solid Al cation is hydrated, in the solid the rest of  H₂O molecules  constitutes a crystallization water.