Bottle of solution of sodium dodecyl sulfate for use in the laboratory. The critical micelle concentration (CMC) in pure water at 25 Â°C is 8.2 mM, and the aggregation number at this concentration is usually considered to be about 62. The micelle ionization fraction (Î±) is around 0.3 (or 30%).
Definition: A pure substance is a sample of matter with both definite and constant composition with distinct chemical properties.
CEPA 1999 defines a substance as any distinguishable kind of organic or inorganic matter, animate or inanimate, that can be released as a single substance, an effluent, waste or a mixture into the Canadian environment.