sulphur dioxide

views updated May 29 2018

sulphur dioxide(SO2) The gaseous product of the oxidation of sulphur, which is released into the atmosphere when fuels containing sulphur compounds are burned. In the atmosphere, a series of reactions oxidize SO2 to particles of sulphate (SO4). Sulphate is also produced in the atmosphere from dimethyl sulphide (DMS, (CH3)2S), released by some species of phytoplankton (especially coccolithophorids). Sulphate crystals act as condensation nuclei, but lower the pH of the water into which they dissolve and SO2 is implicated in acid precipitation.

sulphur dioxide

views updated May 09 2018

sulphur dioxide (SO2) Preservative used in gaseous form or as salts (sulphites) for fruit drinks, wine, comminuted meat, and as a processing aid to control physical properties of flour; also prevents enzymic and non‐enzymic browning. Protects vitamin C but destroys vitamin B1. Prepared by ancient Egyptians and Romans by burning sulphur and used to disinfect wine.

sulphur dioxide

views updated May 18 2018

sulphur dioxide (sulphur(IV) oxide) A colourless liquid or pungent gas, SO2, formed by sulphur burning in air. Sulphur dioxide is produced by burning fossil fuels in power stations; it dissolves in water to give a mixture of sulphuric and sulphurous acids. See also acid rain; air pollution.