The importance of chlorine

Compunds can be decomposed (broken down) using electricity. This process is called eleectrolysis. Electrolysis only works with a direct current (d.c.) such as the correct from batteries.

Electrolysis

The apparatus in the diagram can be used to decompose dilute '''hydrochloric acid. Hydrogen gas is produced at one electrode, and chlorine''' gas is produced at the other.

Using chlorine

Sea water contains a lot of dissolved sodium chloride. Chlorine gas can be obtained from sea water by electrolysis. Chlorine is used to make bleach, and to make plastics such as poly(chloroethene) (also called PVC).

Dangers of chloride

Chlorine is a toxic gas. This makes it useful as a disinfectant because it kills microorganisms. This also makes cglorine hazardous. Chlorine is very useful in industry, and millions of tonnes of it are produced every year. Accidental leaks of chlorine from factories or from tankers could harm or kill many people