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Pure and Impure Substances - Coggle Diagram
Pure and Impure Substances
Types of mixtures
solutions
a homogenous mixture of two or more substances
Oils
any nonpolar chemical substance that is a viscous liquid at environmental temperatures and is both hydrophobic
Alloys
a mixture of two or more elements , where at least one element is a metal .
Emulsions
mixture of two or more liquids in which one is present as droplets, of microscopic or ultramicroscopic size, distributed throughout the other
Separation techniques
Filtration
Residue is insoluble and stays at the top
Filtrate is soluble and is in the bottom of the collection container, ie : test tube
Used to separate insoluble and soluble mixtures
Simple DIstillation
Used to separate a solvent from a solution . It is useful for producing water from salt solution.
Impure substance is heated, steam rises into the condenser, condenser cools down the steam so that pure liquid is collected in the beaker
Fractional Distillation
Removes liquids from a mixture of liquids because liquids have different b.p.s
Mixture is heated to evaporate substance with lowest boiling point
Substance will steam and will get colled in condenser to be collected in the beaker
Chromatography
1.Drop substance at the center of filter paper and allow it to dry
Drop water on substance, one drop at a time.
Paper + rings = chromatogram
Principle : Difference in solubility separates different pigments
Substances travel across paper at different rates which is why they separate into rings
When drawing the baseline use pencil
Water level is also known as mobile phase
Number of rings/ dots = number of substances
If 2 dots are at the same distance on the paper they are the same substance
Retardation Value is used to identify a substance; Rf value = distance moved by solute / distance moved by solvent
to make a colourless substance visible use a locating agent
Pure substances have definite melting and boiling points
Impure substances have lower melting and boiling points
