Химия: решать цепочки:
Al2 -> x -> Al(OH)3 -> AlCl3
Al2S3 -> Al(OH)3 -> AlCl3 -> x

2Al + 3H2SO4 = A2l(SO4)3 + 3H2
Al2(SO4)3 + 6KOH = 2Al(OH)3 + 3K2SO4
Al(OH)3 + 3HCl = AlCl3 + 3H2O
Al2S3 + 6NaOH = 3Na2S + 2Al(OH)3
Al(OH)3 + 3HCl = AlCl3 + 3H2O
2AlCl3 + 3Mg = 3MgCl2 + 2Al