Chemistry

Compounds and Elements

• Properties of a compound is different to the properties of the elements in which it is made.
• When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.
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• Bildunterschrift: Showing that when 2 or more elements mix they chemically combine and their properties change.

Compound Formulae

• Compounds are given a certin chemical formula because they have fixed compositions,using Magnesium Oxide as an example.
• Example-ZnS-Its got this formula becasue its got Zinc atoms and Sulphur atoms chemically combined.
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• Bildunterschrift: Examples of compound formulae

Chromatography

• Chromatography is a technique of separating two or more dissolved solids which are presents in a solution in very small quantities.
• Step 1:Get some Chromatography Paper small enough for it to fit into a beaker
• Step 2:Draw a PENCIL line across it(dont do it with an pen because the ink will flow up the paper with the ink.)
• Step 3:Put 2 spots of ink on the pencil line-one with pen and one with ink.
• Step 4:Get a straightened paper clip an hang it across the beaker with the chromatography paper hung over it.
• Step 5:Pour some water into the beaker making sure it DOESN'T cover the ink.
• Step 6:Watch the ink move up the paper,when the water is 3/4 of the way up take it out.
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Separation of Liquids

• There are many different techniques to separate liquids from solutes.
• For example to separate water from salt water you use evaporation.
• You heat the water up,it will evaporate then you will be left with just the salt
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• Bildunterschrift: Image showing evaporation

Desalination

• Fresh water can be obtained from sea water by the process of desalination.
• Desalination means any process that removes the excess salt and other minerals from water in order to obtain fresh water suitable for animal consumption.
• Another word for this is evaporation
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• Bildunterschrift: Image showing Desalination

Simple Distillation

• Simple distillation is a procedure by which two liquids with different boiling points can be separated.
• It is Evaporation followed by condensation.
• Simple distillation can be used effectively to separate liquids that have at least fifty degrees difference in their boiling points.
• You would have 2 liquids that are not chemically combined(a mixture) .For example one with a boiling point of 100 degrees and one with a boiling point of 50 degrees.
• You would then heat the mixture at 50 degrees so then the liquid with a boiling point of 50 degrees will eventually evaporate and you will be left with the liquid that has a boiling point of 100 degrees.
• Then the liquid with a boiling point of 50 degrees will become condensation and you will have both liquids again only they are not combined in any way.
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• Bildunterschrift: Image of Simple Distillation

Fractional Distillation

• Fractional Distillation is only different to Simple Distillation because instead of separating it into two parts you separate it into a number of different parts(Fractions-hence the name fractional distillation).
• This is mainly used for oils-Crude oil and fuel e.t.c