What happens when solid aluminum and chlorine gas combine?
Aluminum Chloride [AlCl3] is form
When aluminium metal comes in contact with chlorine gas in presence of heat, violent reaction get started and Aluminium chloride powder/granule forms. This is an exothermic reaction. Need to give heat only on time i.e. at the starting of reaction. After starting the reaction and due to exothermic reaction elevated temperature helps in auto reaction in-between aluminium and Chlorine.