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Organic ChemistryC3.5
Love, Heba
Homologous Series
Basic Facts…A homologous series is a group of compounds with the
same general formula - The compounds in a series contain the same elements and have similar molecular structures
Their physical properties change gradually as the compounds increase in size.
Example: The boiling points of compounds in a homologues series increases as the size of the molecules increase.
You probably already know this…
Name No. of Carbons
Meth- 1 Eth- 2
Prop- 3
Alkanes & AlkenesAlkanes ( up to 4 carbon atoms per molecule)
Alkenes ( up to 3 carbon atoms per molecule)
Single bonds Double Bonds ( up to 3 carbon molecules per
Saturated Unsaturated
General formula: General formula:
Doesn’t de-colourise bromine Water
Causes bromine water to turn Colourless
Example: Butane has 4 carbon atoms.
4x2+2 = 10 Hydrogen
Example: Propene 6 hydrogen , 3 carbon
Butane: Propene:
Alcohols ( -OH) General Formula :
up to 3 carbons atoms per molecule
Methanol Ethanol Propanol
Carboxylic Acid - COOH
General Formula :
up to 3 carbons atoms per molecule
Methanoic acid ( NOTE FOR THIS N=0 )
Ethonoic acid N=1 Propanoic acid N=2
Production of Ethanol
Ethanol can be made byFermentation
This includes using YEAST to convert CARBOHYDRATES ( SUGARS) into ALCOHOL
𝐶6 𝐻12𝑂6→2𝐶2𝐻5𝑂𝐻+2𝐶𝑂2
GLUCOSE ETHANOL CARBONDIOXIDE
Note:
- The Carbohydrate can come from any source Often Sugar cane and sugar beet
- The yeast cells contain an enzyme ( a catalyst speeding up the reaction… obv! )
The process… Mix Yeast and solution of Carbohydrate ( e.g. glucose ) in a
clean container.
Seal the container and leave in a warm place
Reason of sealing – To keep mixture in anaerobic conditions ( no oxygen ). If there's oxygen it will convert the ethanol into
ethanoic acid ( vinegar) Ya don’t want that!
Keep at warm place ( e.g. between 30 and 40 degrees ) this ensures fermentation happens at a fast rate b/c its optimum
temperature for enzymes… TOO HOT = ENZYMES DENATURES.
When the concentration of ethanol is around 10/20% the reaction stops because the Yeast is killed off by the alcohol.
Yeast will fall to the bottom of the container, collect alcohol from the top.
To increase percentage created…
Distill fermented mixture. Brandy is distilled from wine, whisky is distilled from fermented Grain and Vodka’s distilled from fermented grain or potatoes!
Different types of HARAM alcoholic drink contain different percentages of ethanol
E.G beer is about 4% while some spirits are around 40%
Fractional Distillation ( making ethanol more concentrated)
Remember: Fermentation produces dilute ethanol below 20% concentration ,
Fractional distillation makes dilute ethanol more concentrated… :
Fractional distillation
1)Fractional distillation separates mixtures using heat2) We want to separate water from ethanol 3) Ethanol has lower boiling point than water 4) When mixture is heated, ethanol evaporates and the vapour rises up the fractionating column, while the water stays there- as liquid 5) A Liebig condenser is used to condense the ethanol vapour by cooling it. 6) The concentrated ethanol can then be collected in a separate flask…
Pro’s & Con’s - Fermentation
Renewable source ( sugar cane and sugar beet) wont run out
Quality of ethanol solution isn't too greatits expensive to concentrate and purify the Ethanol
Production and Issues of Ethanol
Ethene is used to make Ethanol…
Ethene can be reacted with steam to produce Ethanol.
Ethene + Water ( steam) 𝐶2 𝐻4+𝐻2𝑂→𝐶2𝐻5𝑂𝐻
𝐻2𝑂
Ethene is produced from cracking crude oil
Pros & Cons of using Ethene…
At the time, relatively cheap process because Ethene is quite cheap and not much of it is wasted
Its made in a large chemical plant , it can be made continuously and quickly. The quality is very good and doesn’t need further processing unlike fermentation
Ethene is produced from crude oil , it’s from a non-renewable source. Will run out! This means that making ethanol using Ethene will become more expensive!
Effects of Alcohol ON THE BODY
Reduces activity of nervous system. Increases reaction times, impaired judgement , poor
balance, coordination, unconsciousness Excess Alcohol causes dehydration can damage brain
cellsDamaged brain cells = drop brain function, long-term
memory lossSevere damage to liver, leading to liver disease
This is why my lovelies its HARAM
Effects of Alcohol ON SOCIETY
Aggressive behaviourFamily breakdown , loss of job and may become homelessAddiction – AlcoholismHaving sex with random people – increasing chance of
STI’s Drunk drivers can cause accidents leading to death and
serious injuryEconomic costs – A&E, more Police etc.…
Ethene and Ethanoic Acid
WILL UPLOAD LAST TWO SECTIONS BY 2 PM TMO