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.
1 the substance or substances of which any physical object consists or is composed:the matter of which the earth is made. 2  Physicsphysical or corporeal substance in general, whether solid, liquid, or gaseous, esp. as distinguished from incorporeal substance, as spirit or mind, or from qualities, actions, and the like.