Important notes (Organic Compound)
Definition
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Saturated – All the C-C bonds are single
Unsaturated – Not all the C-C bonds are single bonds
Hydrocarbon – They contain carbon and hydrogen only.
Substitution reaction - Atom or group is replaced by another atom or group.
Conditions : Ultraviolet light or sunlight
Addition reaction – when only one product forms from 2 molecules
Homologous series - Family of organic molecules which have the same general formula and
similar chemical properties.
Characteristics :
 Trend in physical properties
 Same/similar chemical properties
 Same general formula
 Successive members differ by CH2
 Same functional group
Structural isomers – Compounds with the same molecular formula but different structures
Cracking – breaks molecules down into smaller ones.
General Formula
Alkane – CnH2n+2
Alkene – CnH2n
Alcohol – CnH2n+1OH / CnH2n+2O
Alkyne – triple bond between carbon - CnH2n-2
Esters -CnH2n+1COOH (esters are sweet smelling liquid and form a layer on water like oil)
Some chemical equations/reactions conditions
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Complete combustion of alkene & alkane– produce carbon dioxide and water
Incomplete combustion of alkene & alkane – produce carbon monoxide and water
3. Combustion of alcohol
Alcohol + Oxygen  Carbon dioxide + water
Differentiate alkene and alkane –
Test : Bromine water
Result : Alkene decolourises bromine water, alkane doesn’t
Cracking – 450 °C – 800 °C, catalyst (zeolites/aluminosilicates/silica/aluminium
oxide/alumina/china/broken pot/chromium oxide), up to 70 atm
Esterification –Alcohol + Carboxylic acid  Ester (alcohol name followed by carboxylic acid)
Conditions : Heat and Catalyst (Concentrated sulfuric acid)
Production of alcohol from alkene (Hydration – a type of addition reaction)
Reagent = Steam
Condition = Catalyst (Phosphoric acid) , 300 °C, 60 atm
Equation = Alkene + Steam (H2O)  Alcohol
Production of alcohol through fermentation
Reactants : Glucose/sucrose/starch
Process is anaerobic
Catalysts : Zymase/Yeast
Condition : 37 °C.
C6H12O6 2CO2 + C2H5OH
How to obtain ethanol from the product : Fractional distillation
Comparison of hydration and fermentation
Hydration advantages
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Purer product
Faster reaction
Continuous process
Hydration disadvantages
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Fossil fuels are non-renewable ‘
Hydration is an equilibrium process meaning lower yield produced
Fermentation advantages
 Renewable feedstock
 Lower temperature means fossil fuels conserved and lower energy costs
 Lower pressure
10. Alcohol  Carboxylic acid
 Oxidation reaction
 Reagent : Acidified potassium manganate (VII)
 Turns colourless
11. Carboxylic acid and Na2CO3
Bubbles/fizzing
12. Boiling point increases as number of carbon increases. The lighter the hydrocarbon, the
more volatile.