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What is the similarity among these drinks?

The above drinks contain …….

Introduction of

Homologous series: Alkanols Common name: AlcoholsGeneral Formula

CnH2n+1OH

or (R-OH)Functional Group - the hydroxyl group

-OH

IUPAC System of Naming

Choose the longest continuous carbon chain that contains the -OH group

The last letter -e of the corresponding alkane is changed to -ol

IUPAC System of Naming Alkanol:

Examples

CH3OH methanol

CH3CH2OH ethanol

CH3CH2CH2OH propan-1-ol

CH3CHCH3 propan-2-olOH

CH3CH2CH2CH2OH butan-1-ol

IUPAC System of Naming Alkanol:

e.g. Name the following compound

Answer : 2-methylpropan-2-ol

CH3

CH3 - C - CH3

OH

Manufacture of EthanolManufacture of Ethanol

There are 2 preparation methods:-

1. Ethanol prepared from hydration of ethene

2. Ethanol prepared from Fermentation of some sugar or starch containing food

Ethanol from ethene

Industrial ethanol is formed from ethene, a petroleum product.

The flow diagram for ethanol manufacture by direct hydration of ethene

Ethene

steam

Furnace ReactorCondensor

ethanol + water is formed

The chemical equation:

CHCH22=CH=CH22 + H + H22O O C C22HH55OHOH

Ethanol from fermentation

Fermentation is the slow breakdown of large molecules to smaller molecules

by micro-organism.

The sources are used

Ethanol has been made by fermentation for several thousand years.

The raw material is some form of starch or sugar such as :

wheatwheat ricerice

potatoespotatoes grapesgrapesappleapple

&&

barleybarley

-Different Source can make different Alcoholic drinks.

Starch/Sugar sources Alcoholic drinkBarley BeerGrape Red/White wineBarley WhiskyGrape BrandyPotatoes VodkaWheat Gin

Micro-organisms used –– Yeast

Zymase is an enzyme present in yeast.Act as catalyst.Conditions: room temperature and pressure.Converts sugar to ethanol and CO2.

For example: Glucose C6H12O6 ,

C6H12O6 (aq) 2CH3CH2OH () 2CO2 (g)

glucose ethanol

CO2

Fermentation of glucose in laboratory

Solution of glucose with yeast

Lime water?COCO22

How to obtain a max. concentration of ethanol from fermentation

The yeast is killed when the proportion of ethanol reaches about 15%.

To obtain a further concentration of the solution, fractional distillation is used.

Max. concentration of the distillate is about 96%.Pure ethanol (absolute ethanol) is obtained by

using CaO (drying agent) to removed the traces of the water.

1. Physical Uses

2. Chemical Uses

• Solvents• Beverage• Disinfectant

• Vinegar Synthesis• Ester Synthesis

3. Fuel • Gasohol (a mixtrue of ethanol and petrol

4. Preparation of ester and ethanoic acid

UsesA. Used as Solvent

A. Polar Group -OH

B. Non-Polar Group CH3CH2-

Water Soluble

Oil Soluble

Hence, Ethanol is Soluble in Both water and Oil

Because Ethanol (CH3CH2OH)contains :

Compare the solubility in water of alkane and alkene with that of alknaol?

Alkane and alkene have very low solubilities in watersince there is no polar group in their structuresbut only hydrocarbon chains, therefore they are only soluble in non-polar solvent.

UsesB. Used as Bervage

Hence, ethanol is used as Bervage

Because Ethanol (CH3CH2OH)contains :

Ethanol is used as bervage because of its GOOD TASTE Thinning of blood and less prone to heart disease PROVIDE A RELEX SENSE

Chemical UsesA. Used as Fuel

As much heat is given out from the above reaction, ethanol can be burnt as fuel

Because burning of Ethanol (CH3CH2OH)is highly exothermic

CH3CH2OH + 4 O2

3CO2 + 3 H2O

Ethanol can be used as Fuel for motor cars.

Advantage: - cleaner then burning petroleum.

Disadvantage:- it is less powerful than petrol

Gasohol is a mixture of ethanol and petrol

B. Used in preparation of Ester

The Ester (with sweet smell) formed can be used as a food flavoring, perfumes and cosmetics.

Because Ethanol (CH3CH2OH) react with Ethanoic Acid to form Ester

Chemical Uses

CH3CH2OH + CH3C OH

O

CH3C OCH2CH3

O

C. Used in synthesis of Vinegar

The Ethanoic acid formed is used as a main component in Vinegar.

Because Ethanol (CH3CH2OH) react with Oxidizing agent to form Ethanoic acid

CH3CH2OHCH3C OH

O

Chemical Uses

[O]

Effects of Alcoholic DrinksAll are poisonousMethanol (CH3OH) is toxic

All alcoholic drinks contain ethanolSmall amounts can help the thinning of blood

and less prone to heart disease, but

Large amounts is dangerous.Taken in large amount has an immediate bad

effect of mental and physical performance.

Effects of Alcoholic Drinks

It affects the normal functioning of the nervous system

Excessive drinking of alcohol over a long period of time, leads to damage of liver and loss of memory

People may become addicted to itMany health, family and social problems

are due to these alcoholics

Advice:DO NOT Addict to Alcoholic drinks

RevisionRevision

The general formula of alkanol is

A. CnH2nOH

B. CnH2n+2OH

C. CnH2n+1OH

D. CnH2n-1OHD

C

B

A

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Introducing Alkanols

The general formula: CnH2n+1OH or ROH

The molecule consist of a functional group - the __________ group (-OH) joined to an _________ group (R-) .

RevisionRevision

hydroxylalkyl

2. Ethanol can be formed by two methods. They are

Equation:

CH2=CH2 + H2O C2H5OH

?Hydration of ethene ?

Fermentation of sugar or starch containing food

Equation:

C6H12O6(aq) CH3CH2OH (l) CO2 (g)

OR

The FIVE uses of Ethanol

1.

2.

3.

4.

5.

6. Use as disinfectant

Use as Solvent

Use as Bervage

Use as Fuel

Use in preparation of Ester

Use in synthesis of Vinegar