1, `2Al(OH)_3`$\buildrel{{575^oC}}\over\longrightarrow$`Al_2O_3+3H_2O`
2, `4Al+3O_2`$\buildrel{{t^o}}\over\longrightarrow$`2Al_2O_3`
3, `Al+3FeSO_4`$\buildrel{{t^o}}\over\longrightarrow$`Al_2(SO_4)_3+3Fe`
4, `Al_2(SO_4)_3+3Ba(OH)_2→2Al(OH)_3downarrow+3BaSO_4downarrow`