Sulfur dioxide, SO_2, and chlorine gas, Cl_2, are two common gases used frequently in a variety of industries. They are rarely introduced together because their products have little use. The reaction of these two gases mainly produces sulfuryl chloride, a toxic and fuming liquid. However, under the right conditions, mixing these two gases can also create sulfuric acid.
Sulfur Dioxide, SO_2, is a pungent gas released by a number of industries, including paper production. It is used frequently in the food industry to preserve and bleach foods. When mixed with water, sulfur dioxide can produce acid rain, which can devastate plant life. Some other names for sulfur dioxide include bisulfite, sulfurous acid anhydride, sulfurous oxide and sulfurous anhydride. Sulfur dioxide condenses, or changes into a liquid, at -10 degrees Celsius. In this phase, it is colorless.
When exposed to room temperatures, chlorine gas, or Cl_2, is a yellow-green gas. It is one of the most reactive and toxic gases known to man. Because of its highly reactive nature, scientists take extra caution to ensure they do not have any other reactive elements in a room. Chlorine gas can be created by mixing two part of hydrochloric acid with either potassium manganate, manganese dioxide or magnesium oxide. The resulting reaction creates one part of water and one part of chlorine gas. Chlorine gas is found in many household chemicals.
More often than not, mixing chlorine gas with sulfur dioxide produces sulfuryl chloride, SO_2Cl_2. This reaction is most efficient when it occurs without the presence of oxygen gas. When oxygen gas is included, at pressures ranging from 10 to 150 Torr, the mixing of chlorine gas and sulfur dioxide creates sulfuryl chloride and sulfuric acid, denoted H_2_SO_4. Because of the chemical nature of its atmosphere, this reaction occurs frequently in the clouds of the planet Venus.
Sulfuryl chloride is a room-temperature liquid that releases high amounts of fumes. These fumes are extremely toxic to humans if inhaled. Direct contact with liquid sulfuryl chloride will result in severe burns. If it is consumed, it can also burn parts of the mouth and the stomach. While it is extremely harmful in humans, sulfuryl chloride is also highly corrosive when it contacts metals. Because of its toxic nature, sulfuryl chloride is rarely used in industry. Its lone use is in insecticide manufacturing where it serves as a solvent.
- Canadian Centre for Occupational Health and Safety, Sulfur Dioxide: Basic Information on Sulfur Dioxide
- The Free Info Society: Chlorine Gas
- "Science Direct"; Laboratory studies on the reactions between Chlorine, Sulfur Dioxide, and Oxygen: Implications for the Venus Stratosphere; William B. Demore, et al.; September 1985
- University College Cork, Department of Chemistry: Sulphuric Acid
- NOAA, CAMEO Channels: Sulfuryl Chloride
- Good Guide, Scorecard, Sulfuryl Chloride: Industrial Uses
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