Methods of Separating Mixtures

• Magnet• Filter• Decant• Evaporation• Centrifuge• Chromatography• Distillation

• Filtrate: as the liquid that passes through the filter

Filtration separates

a liquid from a solid

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 40

Mixture ofsolid andliquid Stirring

rod

Filtrate (liquidcomponentof the mixture)

Filter papertraps solid

Funnel

Paper Chromatography

Setup to heat a solution

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 42

Ring stand

Beaker

Wire gauze

Ring

Bunsen burner

A Distillation Apparatus

liquid with a soliddissolved in it

thermometer

condenser

tube

distillingflask

pure liquid

receiving flaskhose connected to

cold water faucetDorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 282

The solution is boiled and steam is driven off.

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 39

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

Different Types of Fuel Combustion

2 C8H18 + 25 O2 16 CO2 + 18 H2O

__CH3OH +__O2 __CO2 +__H2O

Methanol (in racing fuel)

Gasoline (octane)

Centrifugation

• Spin sample very rapidly: denser materials go to bottom (outside)

• Separate blood into serum and plasma– Serum (clear)– Plasma (contains red blood

cells ‘RBCs’)• Check for anemia (lack of iron)

Blood

RBC’s

Serum

A B C

AFTER

Before

Water Molecules

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 8

The decomposition of two water molecules.

2 H2O O2 + 2 H2

Electriccurrent

Watermolecules

Diatomic Diatomicoxygen molecule hydrogen molecules+

Electrolysis

*Must add acid catalyst to conduct electricity

*H1+

water oxygen hydrogen

“electro” = electricity “lysis” = to split

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 32

Water

Hydrogengas forms

Oxygengas forms

ElectrodeSource ofdirect current

H2O(l) O2 (g) + 2 H2 (g)