Which carbon-chlorine compound did Faraday make by chlorinating ethylene?

Faraday made hexachloroethane by chlorinating ethylene.

The experiment belonged to Faraday’s early chemical investigations of chlorine and carbon compounds. Passing chlorine into ethylene produced a heavily chlorinated compound that is now written as C₂Cl₆. Faraday’s work helped establish that carbon and chlorine could form more than one distinct compound, rather than a single fixed combination.

The result is often confused with carbon tetrachloride, another chlorine–carbon compound associated with Faraday. He obtained carbon tetrachloride from the decomposition of hexachloroethane, so the two substances are connected but are not the same answer. Chloroform and dichloromethane contain hydrogen as well as carbon and chlorine, making them different compounds.

Hexachloroethane is a crystalline solid at room temperature and has been used historically in smoke-producing compositions and other specialized applications. Faraday’s chemistry is best remembered alongside his later electrical discoveries, but this early chlorine research was an important part of his scientific career.