Please enable JavaScript.
Coggle requires JavaScript to display documents.
Purification of substance - Coggle Diagram
Purification of substance
Types of substances
Pure substances
Properties
Melts and boils at a fixed temperature
Shows only one spot on its chromatogram
Mixtures
Properties
Impurities lower the melting point of a solid
Relationship
The higher the impurities, the lower the melting point
Impurities increases the boiling point of a liquid
The higher the impurities, the higher the boiling point
Contains 2 or more substances that are not chemically combined
Can be separated physically into pure substances through the process of purification
Separating methods
Filtration
Used to separate an insoluble solid from a liquid
The solid that remains is called the residue
The liquid that passes through the filter paper is called the filtrate
Evaporation to dryness
Heating the solution until all the water has been removed
Only used for solids that do not decompose on heating
Crystallisation
Heating the solution until most of the water has been boiled off to obtain a saturated solution
Left to cool off to form a crystal
A saturated solution is one that contains the maximum amount of solute that cannot dissolve anymore solute
Only used for soluble solids that decompose on heating
Steps
Heat the solution until saturation
Allows saturated solution to cool for crystals to form
Filter the mixture and collect crystals as residue
Wash the crystals with distilled water and dry the crystals with filter paper
Simple distillation
Used for mixtures with different boiling points
1) Boiling chips
To ensure the smooth boiling of the solution
2) Thermometer
To check the boiling point of the substances
Condensor
To change the gas of the separated solution back in a liquid
Fractional distillation
Used for mixtures with close boiling points
Fractionating column contains glass beads that provide a larger surface area for the vapour to condense
The liquid with the lowest boiling point is distilled and collected first
The liquid with the highest boiling point will be collected last
Paper chromatography
Used to find out the components found in dyes in food colouring and ink
Used to separate two or more components that dissolve in the solvent used
The most soluble component will travel the furthest distance in the chromatogram
