Chap 1 - Methods of purification Flashcards
Filtration uses
Separate insoluble solid from liquid
How filtration works
Particles smaller than filter paper pass while particles larger than filter paper trapped
When to use filtration
Solid insoluble in liquid
What is Evaporation
Supply heat to remove liquid
Evaporation process
The solute has higher boiling point than solvent ➡ solvent boils off ➡ solute leaves
Why Evaporation
To obtain solid form liquid
When to use evaporation
Solute thermally stable and not compose upon heating
What is distillation
Process to separate liquid from a solution of solute
How does distillation works
Boiling a liquid and condense vapour
Why use distillation
Obtain pure solvent from a solution of solvent
When is crystallisation used
When substance decompose when heated strongly
How crystallisation works
The solution is evaporate and sill saturated and allow to cool ➡ dissolve solid from crystals
What is crystallisation
Method to obtain pure solvent from its solution
What is decomposition
Substance that lose water of crydtallisation
How Fractional distillation works
- Mixture of liquid is heated and it vapourised
- The vapour of higher boiling point condenses on the cool surfaces in the fractionating column and falls back into the flask
- The vapour of a lower point reaches the upper part of the column and is distilled. This vapour passes though the condenser and undergo cooling. It changes to liquid and flows down the liner tube go the condenser
- The liquid collected as distillate in the receiver
What is Fractional distillation
Separation of a mixture of MISCIABLE ( can mix to form solution ) liquids with DIFFERENT BOILING POINTS
What is the difference Fractional distillation and distillation
Distillation can only obtain a liquid while Fractional distillation can obtain many fractions of liquid
When and why Fractional distillation is used
Mixture of liquids that is miscible and have different boiling points
Similarities fractional distillation and distillation
Both involve evaporation / boiling / and condensation
What is Chromatography
Method to separate and identify two or more components that dissolve in the same solvent
How Chromatography works
Substance that dissolves in the solvent ➡ more soluble component travel further up the paper and the less soluble component will travel a shorter distance
How is Chromatography use
- Identify drugs
- Check if there is pesticides in vegatable
What is the difference with Chromatography and the other methods
Others seprate but not identify components in mixture
What is the physical prosperities to consider in Chromatography
Solubility in the same solvent
What is the property of a pure substance
Its has fix boiling and melting point
What is the property of a impure substance
They do not have fix boiling and melting point ➡ increase or decrease boiling / freezing point
