Chlorine dioxide

Chlorine Dioxide is a chemical compound with the formula ClO2. This yellowish-green gas crystallizes as bright orange crystals at −59 °C. As one of several oxides of chlorine, it is a potent and useful oxidizing agent used in water treatment and in bleaching.

Chemical Properties

Chlorine dioxide is a neutral chlorine compound. It is very different from elementary chlorine, both in its chemical structure and in its behavior. One of the most important qualities of chlorine dioxide is its high water solubility, especially in cold water. Chlorine dioxide does not hydrolyze when it enters water; it remains a dissolved gas in solution.

Production

Chlorine dioxide is produced from sodium chlorate and is prepared in situ by reducing sodium chlorate in a strong acid solution with a suitable reducing agent such as methanol, hydrogen peroxide, sulfur dioxide or hydrochloric acid.

Uses

Chlorine dioxide is used for the disinfection of drinking water and is produced in a number of ways. It is also used for the oxidation of pollutants in water and for the bleaching of cellulose, flour, oils, and fats.

Safety

Chlorine dioxide is a hazardous compound and should be handled with caution. It can react explosively with organic materials at high concentrations.

See Also

• Oxides of chlorine
• Water treatment
• Bleaching