Separating mixtures: filtration, distillation, and chromatography

Because the substances in a mixture are not chemically combined, they can be separated by physical methods that use differences in their properties. Filtration passes a mixture through a filter that lets liquid through but traps solid particles, separating sand from water. Evaporation removes a liquid solvent by heating, leaving a dissolved solid behind, the way salt can be collected from seawater. Distillation boils a liquid mixture and then cools the vapor to collect the part with the lower boiling point, separating substances with different boiling points; it is used to purify water, and a version called fractional distillation separates crude oil into gasoline, diesel, and other fuels. Chromatography separates dissolved substances by how strongly each one is attracted to a moving solvent compared with a stationary material like paper: in paper chromatography, ink separates into colored bands because each dye travels a different distance. A magnet can pull iron filings out of a mixture, and decanting pours a liquid off a solid that has settled. Choosing a method starts with asking which property, such as particle size, boiling point, solubility, or magnetism, differs between the parts of the mixture.

This explanation is AI-generated and can occasionally be wrong. 🚩 Report