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.
volatile - a volatile substance; a substance that changes readily from solid or liquid to a vapor; it was heated to evaporate the volatiles. 1  substance - the real physical matter of which a person or thing consists; DNA is the substance of our genes.