1. Alcohols

2. Alcohols Methanol CH3OH Ethanol C2H5OH Propan-1-ol C3H7OH
Butan-1-ol C4H9OH
Butan-2-ol C4H9OH

3. Methanol CH3OH

4. Ethanol C2H5OH

5. Propan-1-ol C3H7OH

6. Butan-1-ol C4H9OH

7. Propan-2-ol CH3CH(OH)CH3

8. Butan-2-ol CH3CH(OH)C3H7

9. Classification of alcohols
Primary alcohol: contains one carbon atom directly attached to the carbon that contains the hydroxyl group, e.g propan-1-ol

10. 2. Secondary alcohol: contains two carbon atoms directly attached to the carbon that contains the hydroxyl group, e.g. propan-2-ol

11. Physical properties Physical state: Liquid
Boiling points much higher than the corresponding alkanes, due to polar OH group

12. Physical properties Solubility of methanol in
(i) cyclohexane – not very soluble methanol is polar cyclohexane is not
(ii) water - completely soluble because it is polar.
As alcohol molecule gets bigger the polar part becomes less significant so the alcohol becomes less soluble in water and more soluble in cyclohexane

13. Butan-1-ol is
(i) soluble in cyclohexane
(ii) not very soluble in water
The polar OH group is becoming less significant as the molecule gets bigger

14. Comparison with water Both have polar OH groups
Alcohols have a non-polar part
Both form hydrogen bonds between their molecules
Water is more polar and has a greater capacity to form hydrogen bonds and so has a higher boiling point than methanol or ethanol

15. Methanol Methanol: is toxic (can cause blindness, insanity and death)
It is added to industrial alcohol to prevent people drinking it. This mixture is called methylated spirits.
The methanol acts as a denaturing agent – it renders a substance unfit for purpose without destroying the usefulness or applications of the substance. A purple dye is often added as a warning.

16. Ethanol
Ethanol: is produced by fermentation. Fruits provide the sugar and yeast may need to be added.
The enzyme zymase in yeast catalyses the reaction.
C6H12O C2H5OH CO2

17. Alcoholic Drinks Ingredient Drink % (v/v) alcohol Grapes Wine 12
Apples
Cider
4.5
Malted grain
Beer 5

18. Ethanol
To produce drinks of higher alcohol concentration the fermented liquids must be distilled.
Spirits (whiskey, brandy, gin, vodka) contain 40% alcohol.

19. Gasohol
Ethanol obtained from sugar cane is used for making gasohol in Brazil. This is then used as a fuel.

20. Uses of ethanol Alcoholic drinks Fuel
Solvent (can dissolve both polar and non-polar solutes)