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Chemistry
C7




Alkanes

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State
Methane, Ethane and Propane are gasses at room temperature.
Pentane and above are liquid at room temperature
Amount of C's increase as you go down.

Chemical Properties
Alkanes are a family of hydrocarbons
o Carbons surrounded by single covalently bonded hydrocarbons
Alkanes burn to give carbon dioxide and water…

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Chemical Properties
All alcohols burn.
Methanol and ethanol are both highly fl ammable and are used as fuels.
Methanol can burn with an invisible fl ame, making it dangerous to use in the laboratory.
Reactions between alcohols and alkali metals are very similar to the reactions between water and
sodium.…

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Carboxylic acids have the functional group COOH
Reacts like other acids
o Reacts with metals to salt and hydrogen
o With Alkalis to form salt and water
o With Carbonates to give salt, water and carbon dioxide
Stink
Ethanol + Oxygen Ethanoic acid + water




Esters
Esters have function group…

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Preparation of Esters
An alcohol can react with a carboxylic acid to make esters.
The reaction happens on warming the alcohol and the acid in the presence of a little sulfuric acid to
act as a catalyst.
Reactions of esters do not go to completion.
Reactions that do not go…

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They transfer heat energy to the surroundings
o i.e. they give out heat
o Combustion of carbon is an example of an exothermic reaction
o Carbon + oxygen Carbon dioxide + heat energy
Neutralising alkalis with acids and many oxidation reactions also are exothermic
Energy change can be shown using…

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Can be shown on an energy level diagram




Breaking a chemical bond requires a lot of energy ­ endothermic process
o More energy is required to break old bonds than is released when the new bonds are
formed




When a new chemical bond is formed, energy is given out ­…

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Answer:
1) The energy used to break bond is... (Hydrogen + Oxygen)
2 X H-H + O=O = (2 X 436) + 496
= 1368kJ
2) The energy used t make bonds is... (Water)
2 x H-O-H = 2 X (2 X 463)
= 1852kJ
3) The energy change =…

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Both the forward and the backward reactions are still occurring, but at the same rate
There is no overall change in concentration of the substances
Dynamic equilibrium may be used to explain the difference between a strong acid and a weak acid

Strong Acids
Hydrochloric acid, nitric acid and sulfuric…

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The chromatogram can be compared to standard chromatogram (standard reference materials) of
known substances to identify the different chemicals
The solvent that is used to move the solution is called the mobile phase
A range of aqueous and non-aqueous solvents may be used
Aqueous solvents are water based, whereas non-aqueous…

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