Aluminium & Bromine Reacts Dramatically

This spectacular demonstration shows the highly exothermic vigorous reaction between aluminium foil and bromine performed in a big-sized borosilicate test tube. 2Al(s) + 3Br2 (l) = Al2Br6 (s)
Safety : Bromine is toxic if inhaled or swallowed. It can damage the respiratory system and the digestive system. It can also cause damage if spilled on the skin. It causes severe burns to eyes and skin. Safety goggles and gloves must be worn to handle the liquid bromine and the experiment should be done in a fume cupboard as both the reactants and the products are hazardous. It is also to be noted that Aluminium bromide reacts vigorously and exothermically with water, releasing HBr fumes which cause severe burns.
Some Important Notes & Explanations :
(Ref : https://chemdemos.uoregon.edu/demos/Reaction-of-Aluminum-and-Bromine )
This reaction can be used as an example of a redox reaction and can be used to introduce the concept of ionic vs covalent bonding. It is also an example of an exothermic formation reaction that produces a lot of light, so it can be used to introduce the concepts of exothemicity and enthalpies of formation.
Aluminum bromide is hygroscopic and fumes in air, forming a white cloud that looks orange because it is mixed with bromine vapor. Aluminum has a Pauling electronegativity of 1.5 and bromine has an electronegativity of 2.8. The resulting electronegativity difference of 1.3 for the Al-Br bond falls well within the commonly accepted range for polar covalent bonds. So this is an example of a compound between a metal and a non-metal in which the bonds have a great deal of covalent nature. Since the aluminum bromide produced in this reaction is formed from elements in their standard states, this is an example of a formation reaction. The heat of formation of aluminum bromide is -526 kJ/mol. This accounts for the exothermic nature of the reaction. Since aluminum bromide is electron deficient, it is a Lewis acid and reacts strongly with water, which accounts for the way it fumes when exposed to the moisture in air. "Some of the aluminum bromide is produced as fumes, causing the white smoke .... In addition, aluminum bromide reacts violently with water to produce HBr and aluminum hydroxide or oxide."

Видео Aluminium & Bromine Reacts Dramatically канала Dr.Amal K Kumar