Separation Techniques

Methods of Separating Mixtures Magnet Filter Decant Evaporation Centrifuge Chromatography Distillation

Filtration separates a liquid from a solid Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 40 Mixture of solid and liquid Stirring rod Filtrate (liquid component of the mixture) Filter paper traps solid Funnel

Paper Chromatography

Chromatography: Separates substances on the basis of differences in solubility in a solvent.

Setup to heat a solution Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 42 Ring stand Beaker Wire gauze Ring Bunsen burner

The solution is boiled and steam is driven off. Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 39

Distillation Apparatus Salt remains after all water is boiled off. Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 39

No chemical change occurs when salt water is distilled. Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 40 Saltwater solution (homogeneous mixture) Distillation (physical method) Salt Pure water

Separation of a sand-saltwater mixture. Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 40

Centrifugation Spin sample very rapidly: denser materials go to bottom (outside) Separate blood into serum and plasma –Plasma = less dense –Erythrocytes = red blood cells Check for anemia (lack of iron)

Water Molecules Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 8

The decomposition of two water molecules. 2 H 2 O  O H2H2 Electric current Water molecules Diatomic oxygen molecule hydrogen molecules +