Britannica
Sources used in this answer
- separation and purification - Distillation
- chromatography
- separation and purification - Basic concepts of separations
- separation and purification - Filtration and screening
- separation and purification - Exclusion and clathration
- separation and purification - Crystallization and precipitation
- chemical reaction: Top Questions
How can mixtures be separated without changing the compounds in them?
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chemical compound
Methane, in which four hydrogen atoms are bound to a single carbon atom, is an example of a basic chemical compound. The structures of chemical compounds are influenced by complex factors, such as bond angles and bond length.
Mixtures can be separated into their individual components without altering the chemical identity of the substances involved by utilizing physical processes. These methods rely on differences in the physical properties of the components, such as boiling point, particle size, solubility, or affinity for different phases.1234567
Common physical separation techniques include:
- Distillation: Separates components based on differences in boiling points. By heating a liquid mixture, the substance with the lower boiling point vaporizes first and can be collected after condensation.3
- Chromatography: Separates solutes by distributing them between a mobile phase and a stationary phase. Components migrate at different rates based on their affinity for these phases.4
- Filtration: Uses porous materials to separate particles based on size, commonly used to remove solids from liquids.5
- Crystallization: Exploits differences in solubility. By cooling a saturated solution, a less soluble component can be isolated as it forms solid crystals while others remain dissolved.7
- Size-exclusion chromatography: Separates molecules based on their size, where larger molecules are excluded from porous matrices and emerge faster than smaller ones.6
These methods are distinct from chemical reactions, which rearrange atoms to create entirely new substances.2