What is the reaction of aluminium with hydrofluoric acid?

[aadaasdark8072]

Pretty straightforward. In general, the reaction of aluminum (Al) and hydrofluoric (HF) produces aluminum fluoride (AlF3) and hydrogen (H2). The balanced equation is:

2Al +6HF → 2AlF3 + 3H2

[ohapuqa]

Fluoric acid is generally acidic in aqueous solutions, but it's a strong lewis acid, and hydrofluoric acid is very acidic at high concentrations.
It reacts with aluminum mainly because of the formation of extremely stable complexes, stable anions of fluoroaluminate, rather than aluminum ions, making the reaction easy to carry out.
4 hf + Al = HAlF4 + 3/2 h2
It can even be complexed into hexafluoroaluminic acid.