Al $\overset{1}{⟶}$ $AlCl_{3}$ $\overset{2}{⟶}$ $Al(OH)_{3}$ $\overset{3}{⟶}$ $Al_{2}O_{3}$ $\overset{4}{⟶}$ $Na[Al(OH)_{4}]$ $\overset{5}{⟶}$ $Al_{2}(SO_{4})_{3}$ $\overset{6}{⟶}$ $Al(OH)_{3}$ $\overset{7}{⟶}$ $AlCl_{3}$ $\overset{8}{⟶}$ $Na[Al(OH)_{4}]$
1) $2Al + 6HCl = 2AlCl_{3} + 3H_{2}↑$
$2H^{+} + 2ē ⟶ H_{2}^{0}$ − окислитель
$Al^{0} - 3ē ⟶ Al^{+3}$ − восстановитель
2) $AlCl_{3} + 3NaOH = 3NaCl + Al(OH)_{3}↓$
$Al^{3+} + 3Cl^{-} + 3Na^{+} + 3OH^{-} ⟶ 3Na^{+} + 3Cl^{-} + Al(OH)_{3}↓$
$Al^{3+} + 3OH^{-} ⟶ Al(OH)_{3}↓$
3) $2Al(OH)_{3} = Al_{2}O_{3} + 3H_{2}O$
4) $Al_{2}O_{3} + 2NaOH + 3H_{2}O = 2Na[Al(OH)_{4}]$
$Al_{2}O_{3} + 2Na^{+} + 2OH^{-} + 3H_{2}O ⟶ 2Na^{+} + 2[Al(OH)_{4}]^{-}$
$Al_{2}O_{3} + 2OH^{-} + 3H_{2}O ⟶ 2[Al(OH)_{4}]^{-}$
5) $2Na[Al(OH)_{4}] + 4H_{2}SO_{4} = Al_{2}(SO_{4})_{3} + Na_{2}SO_{4} + 8H_{2}O$
$2Na^{+} + 2[Al(OH)_{4}]^{-} + 8H^{+} + 4SO_{4}^{2-}$ ⟶ $2Al^{3+} + 3SO_{4}^{2-} + 2Na^{+} + SO_{4}^{2-} + 8H_{2}O$
$[Al(OH)_{4}]^{-} + 4H^{+} ⟶ Al^{3+} + 4H_{2}O$
6) $Al_{2}(SO_{4})_{3} + 6NaOH = 3Na_{2}SO_{4} + 2Al(OH)_{3}↓$
$2Al^{3+} + 3SO_{4}^{2-} + 6Na^{+} + 6OH^{-}$ ⟶ $6Na^{+} + 3SO_{4}^{2-} + 2Al(OH)_{3}↓$
$Al^{3+} + 3OH^{-} ⟶ Al(OH)_{3}↓$
7) $Al(OH)_{3} + 3HCl = AlCl_{3} + 3H_{2}O$
$Al(OH)_{3} + 3H^{+} + 3Cl_{-} ⟶ Al^{3+} + 3Cl^{-} + 3H_{2}O$
$Al(OH)_{3} + 3H^{+} ⟶ Al^{3+} + 3H_{2}O$
8) $AlCl_{3} + 4NaOH(изб.) = Na[Al(OH)_{4}] + 3NaCl$
$Al^{3+} + 3Cl^{-} + 4Na^{+} + 4OH^{-}$ ⟶ $Na^{+} + [Al(OH)_{4}]^{-} + 3Na^{+} + 3Cl^{-}$
$Al^{3+} + 4OH^{-} ⟶ [Al(OH)_{4}]^{-}$