The formula for aluminum chloride is written as AlCl3. This means there are three atoms of chlorine for every atom of aluminum in the compound.
Combining aluminum and chlorine gas yields a compound called aluminum chloride. This compound is also called trichloroaluminum and aluminum trichloride, according to PubChem Compound. In medicine, aluminum chloride has two applications. Because it causes tissues to contract, some dentists use it to control bleeding during dental procedures. This compound is also found in products that control excessive sweating. The most common side effects of aluminum chloride are tingling, itching and irritation at the application site.