Question

What would the products be when aluminum chloride (which contains Al3+ and Cl- ions) is melted and electrolyzed? Write half equations to show what goes on at each electrode.

Answer 1

The product of electrolysis : Al at cathode and Cl₂(chlorine) at anode

Further explanation

Given

Aluminum chloride compound

Required

The product of electrolysis

Solution

The rule :

The reaction at the cathode(the negative pole) :

1. the reduced active metal is water, other than that the metal will be reduced

2. H⁺ of the acid will be reduced

The reaction at the anode((the positive pole) :

1. if the electrodes are not inert then the metal is oxidized

2. If inert then:

a. OH⁻ from the base will be oxidized

b. The halogen metal will oxidize

In the electrolysis of molten AlCl₃ with an inert electrode, the cation will be reduced at the cathode and the anion will be oxidized at the anode

Cathode : Al³⁺ + 3e⁻ ⇒ Al(s)

Anode : 2Cl⁻⇒Cl₂(g) + 2e⁻