Q. How can paraquat be described in chemical terms?
A. Paraquat is a broad spectrum non-selectiveDescription A chemical product used for eliminating all types of weeds (annual and perennial grasses and broadleaved weeds). Authoritative On-line References and Resources http://www.weeds.iastate.edu/ An invaluable source of contemporary information about herbicides and weeds from Iowa State University. herbicide. It belongs to the Bipyridylium family of herbicides. Pure paraquat salts are white and the technical products, yellow. They are crystalline, odorless, hygroscopic powders. Paraquat is slightly soluble in alcohol and practically insoluble in organic solvents. Paraquat is non-explosive and non-flammable in aqueous formulations. It is corrosive to metals and incompatible with alkylarylsulfonate wetting agents. It is stable in acid or neutral solutions, but is readily hydrolysed by alkali.
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Structural formula |
Paraquat is a strong cation and stays where applied |
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|---|---|---|
| Description | White crystalline solid | like sucrose |
| Solubility | Very soluble in water. Not soluble in fat | like sodium chloride |
| Vapor pressure | Negligible, below 1 x 10-9 mm Hg | like copper coins |
| Toxicity (45.6% technical) |
Inhalation not possible. Oral LD50 (technical material in the rat) = 283mg/kg |
like gasoline |
Molecular structure of paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride)