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 is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be chemical elements, chemical compounds, ions or alloys. chemical compound can be either atoms bonded together in molecules or crystals in which atoms, molecules or ions form a crystalline lattice. Compounds based primarily on carbon and hydrogen atoms are called organic compounds, and all others are called inorganic compounds.