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Reaction Reagents Conditions Observations
Combustion Alcohol Excess oxygen Complete combustion burns with a
Oxygen Flame or spark blue flame leaving no soot
Incomplete combustion burns with a
yellow flame leaving soot

(Partial) Primary alcohol Immediate distillation Colour change from orange
Oxidation of Acidified(by dilutesulphuric acid) otherwise the aldehyde (dichromate(VI) to…

Page 2

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ethanal as it has a low
bpt.
Distillation
Oxidation of Secondary Alcohol Heating under reflux Colour change from orange
Secondary Acidified (by dilute sulphuric acid) (dichromate(VI) to blue-green
Alcohol to sodium/potassium dichromate(VI) chromium(III))
Ketone solution
Oxidation of Not possible with most oxidising agents N/A If acidified sodium/potassium
Tertiary (including acidified…

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Alcohol Alcohol Moist If then tested with nitric acid and
reacting with Red allotrope of phosphorous (makes Heat under reflux silver nitrate, halide ions will be able
phosphorous phosphorous tribromide, tri-iodide and to be seen.
halide. trichloride in situ
. Other product is This shows an ­OH group is present…

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Add acidified potassium manganate(VII) Solution turns from dark pink to Unsaturated compound
Shake at standard conditions colourless/pale pink Could be an alkene
Manganate (II) ions formed
Add alkaline potassium manganate (VII) Solution turns from dark pink to: Unsaturated compound
o Green if manganate(VI) ions are Could be an alkene
formed…

Page 5

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Add sodium carbonate to neutralise Copper(II) complex ions reduced to
anything copper(I) ions.
Warm gently Benedict's solution does the same
Sodium/potassium Effervescence Carboxylic acid
carbonate/hydrogencarbonate CO2 ­ bubbled through limewater turns
-COOH group present
Standard conditions milky.
Add carboxylic acid Fruity/gluey smell (ester) Alcohol present
Add small amount of concentrated…

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Production of ethanol

Definition:

Biofuel ­ A fuel derived from renewable biological sources

Carbon neutral ­ An activity that has no net annual carbon (greenhouse gas) emissions to the atmosphere



Importance

-Fuel

- Solvent (cosmetics)

- Intermediate in chemical processes



Production

Method 1 ­ Hydration of ethene

Crude oil fractions…

Page 7

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CH2=CH
H
2+ <=> C
2O
2H 5OH





Method 2 (No longer used industrially)­ Electrophilic addition using sulphuric acid (Mechanism in 3.2.9)

Concentrated sulphuric acid is added to ethene.



Method 2 ­ Fermentation of sugars

Carbohydrates from plants are broken down into sugars and then metabolised by yeast during anaerobic…

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Plants with high starch content ­ Starch is polymer of glucose so must first be broken down (by other bacteria). Used to make motor fuel in USA.

Plant waste ­ Lots of cellulose, a polymer of glucose, in wood shavings, wheat straw and corn husks. Need bacteria to break down…

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Methanol usually used as chemical feedstock (starting place for making other chemicals). Made using copper catalyst. CO(g) + 2H CH
2(g) 3OH(g)
The
starting mixture of CO and H2is called synthesis gas and is made from propane or methane with steam. Favours high pressure and low temperature.
Compromise of 500K…

Page 10

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2 mols of CO2released per mol of glucose Total = -4



3. Combustion of ethanol

2C
2H5OH
+ 6O2->4CO2+ 6H2O



(Carry the 2 mols of ethanol made across)

4 mols of CO2 released per mol of glucose (from the start of the ethanol equation) Total = 0



In theory ethanol…

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