Iron (III) chloride is commonly known as ferric chloride. It is mostly an industrial compound that is rarely seen in nature.
The simple molecular formula of this compound consists of one iron atom bonded with three chlorine atoms. Therefore, the molar mass is just above 162 grams in anhydrous form. The melting point for this substance is 306 degrees Celsius. Iron (III) chloride gives off a slight odor similar to hydrogen chloride.
This combination of iron and chlorine is most frequently used to treat sewage water and assist in the production of drinking water. The hydroxide ions in the water react with the iron to form flocs of iron (III) hydroxide. These remain suspended in the solution and remove contaminants.
There are other laboratory uses for this compound as well. Researchers use it to catalyze certain reactions. They also use it to detect phenol compounds when synthesizing organic products, such as aspirin.