Anhydrous Aluminum Chloride Extra Pure is a high-purity, white to pale yellow crystalline compound widely used in laboratory chemistry as a powerful Lewis acid catalyst. It plays a key role in organic synthesis, particularly in Friedel–Crafts alkylation and acylation reactions, and is essential in the study of electrophilic aromatic substitution mechanisms. Due to its extreme moisture sensitivity, it hydrolyzes rapidly upon exposure to air, releasing hydrogen chloride gas, and must be handled under strictly dry conditions. The extra pure grade ensures low levels of impurities, making it suitable for high-precision research and moisture-sensitive experimental work. It should be stored in airtight, moisture-free containers in a cool, dry environment, preferably under an inert atmosphere.