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.
A chemical substance[1] also known as a pure substance is a form of matter that has constant chemical composition and characteristic properties.[2] It cannot be separated into components by physical separation methods, i.e., without breaking chemical bonds.[3] Chemical substances can be chemical elements, chemical compounds, ions or alloys.