Methods Of Separation Flashcards
What are the methods of separation?
Filtration Paper chromatography Crystallisation Distillation Fractional distillation
What is filtration used for?
For separating an insoluble solid from a liquid
Or
An insoluble solid from a soluble solid
How do you carry our filtration?
By pouring the solid and liquid through filter paper in a filter funnel
What is paper chromatography used for?
For separating liquids by dissolving them in a solvent e.g. Separating ink colours or plant dyes
How do you carry out paper chromatography?
An example is separating ink colours or plant dyes
A dot of the ink/dye would be drawn into a piece of paper
It would then be left in water, which acts as a solvent
Because different colours have different solubility levels, some colours would travel further up on the paper
What is crystallisation used for?
Mainly used for purifying substances by forming crystals from a concentrated solution
What does crystallisation refer to?
The forming of solid crystals from a homogenous mixture (a solution)
Example of crystallisation?
Forming pure salt crystals-
Dissolve the impure salt in a solvent such as water
Allow to cool - pure salt crystals will form at the bottom of the water because it is in high concentration
The impure substances will be left in the water because they are low in concentration
What is distillation used for?
Separating a liquid from a solution
Separating two liquids with different boiling points
Example of distillation?
Separating water from a salt solution
Heat solution at the liquids boiling point - it will leave the solution as a vapour
Vapour condenses into a liquid - will fall into the beaker
What is fractional distillation used for?
Used to separate complex mixtures of liquids based on their boiling points
Eg crude oil
Dyes that make up ink differ in two ways:
How strongly they bond to paper
How soluble they are with a solvent
