Separation Techniques

So Last class we did a notes from Miss Chen Notes. Here's all the info .
*Basis for separation : Different components , Different properties.
*Strategy: Devise a process that discriminates between components with different properties..

High Density/Low Density

Volatile/nonvolatile

Soluble/Insoluble

...

Separation

*Components in a mixture retain their identities: mixtures components have different porperties

Some Basic Technic:

-Filtration: Select component by particle size.

-Floatation: Select component by density

-Crystallization & Extraction: Select component by Solubility

-Distillation: Select component by boiling point.

Hand Separation & Evaporation

-Hand separation (solids and solids)

*mechanical mix or heterogeneous mix can be separate by using magnet or sleeve

-Evaporation (solid dissolved in liquid solution)

-Boil away the liquid and the solid remains.

Filtration: (solids(not dissolved)and liquids)

-Pass a mix that contains solid particles through a porous filter.

-If pores are smaller than particles,solid particles stay on filter and liquid/gaseous components pass through often used after separate by precipitation

-Use filter paper- residue left in

Crystallization (solid in liquid)

-Precipitation: Converse solute to solid form by chemical or physical change.

-Solids are separated by filtration or floatation.

-Evaporate or cool - solid comes out as pure crystal.

Gravity Separation: (solids based on gravity)

A centrifuge whirls the test tube around at high speeds forcing the denser materials to the bottom. Workds best for small volumes.

Solvent Extraction
-Component moves in a solvent shaken with mixture.
-Mechanical Mixture (solid and Solid) use liquid to dissolve one solid and the other one dissolved.
-Solution: Solvent is insoluble with solvent already present. Solvent dissolves one or more substances and leaves unwanted substances behind.

Distillation (Liquid in Liquid Solution)
-heating a mixture can cause low-boiling components to volatilize (vaporize)
-Distillation is collecting and condensing volatilized component.
-Liquid lowest boiling temperature , always boils first.

Chromatography
-Flow the mixtures over a materials that retains some components more than others
-Mobile phase sweeps the sample over a stationary phase (as the wind sweeps the swarm over the flower bed)
-Separate very complex mixtures

Sheet Chromatography
-Paper chromatography (PC)
Liquid soaked into a sheet in stationary phase ,some take longer than others
-Thin layer chromatography (TLC)
Stationary phase is a thin layer of absorbent (Al2O3 or SiO2) coating a sheet of plastic bond the absorbant strongly and other weakly.