Question

I wonder if we can get aluminium metal by adding alkali metal (ex. Li,Na) to aluminium chloride solution?or maybe what will happen if we mix aluminium chloride hexahydrate with sodium metal?

Answer 1

When alkali metals react with aluminium chloride solution, they form a complex ion called sodium tetrahydroxoaluminate. Mixing aluminium chloride hexahydrate with sodium metal would result in the formation of sodium hydroxide and aluminium hydroxide, not aluminium metal.

Step-by-step explanation:

When alkali metals (such as Li or Na) are added to an aluminium chloride solution, they react to form a complex ion called sodium tetrahydroxoaluminate:

Na[Al(OH)4](aq) + H3O+(aq) → Al(OH)3(s) + Na+(aq) + 2H2O(l)

On the other hand, when aluminium chloride hexahydrate is mixed with sodium metal, the sodium metal would react with water molecules present to produce hydrogen gas and sodium hydroxide, so aluminium metal would not be obtained:

2AlCl3•6H2O(s) + 6Na(s) + 18H2O(l) → 6NaOH(aq) + 2Al(OH)3(s) + 6H2(g) + 6HCl(aq)