1. Alcohols and Ethers
AH Chemistry Unit 3(b)

2. Alcohols

3. Physical properties
When comparing the boiling point of ethanol with an alkane, which alkane would you compare it with?
Which would have the higher boiling point?
Why?

5. Alcohols exhibit hydrogen bonding.
As a result, they exhibit higher boiling points than (most) other organic compounds of similar molecular mass.

6. Which is more soluble in water: ethanol or hexan-1-ol?
Why?

7. The lower alcohols are miscible with water but as their chain length increases their solubility in water decreases.

8. Preparation of alcohols
There are 2 principle methods for producing alcohols in industry What are they?
Acid-catalysed hydration of alkenes (electrophilic addition)
Nucleophilic substitution of halogenoalkanes

9. Reactions of alcohols With metals Dehydration With carboxylic acids
produces alkoxides
Dehydration
produces alkenes
With carboxylic acids
produces esters, slowly
With acid chlorides
produces esters, more vigorously

10. Acid chlorides

11. Carboxylic acids can be converted into acid chlorides by reaction with:
Thionyl chloride
Phosphorus(III) chloride
Phosphorus(v) chloride

12. Producing esters
Use full structural formulae to illustrate how ethyl propanoate can be produced from an alcohol and an acid chloride.
What type of reaction is this?

13. Ethers

14. General formula

15. Uses Solvents Reasons: Dissolve many organic compounds
Volatile (so removed easily by distillation)

16. Preparation of ethers Q: How can you prepare an ether in the lab?
A: Reaction of a halogenoalkane with a metal alkoxide.
Q: What type of reaction is this?
A: Nucleophilic substitution

17. Naming ethers
Methoxyethane
Methoxymethane
Ethoxypropane

18. Naming Ethers Name the longest continuous chain e.g. pentane
Name the alkoxy group by removing “yl” from the substituent name and adding “oxy” e.g. propyl becomes propoxy
Add the appropriate number in front of the substituent if the ether is branched e.g. 3

20. Name a halogenoalkane and metal alkoxide combination you could use to prepare ethoxybutane.
Name the ether produced by reacting 1-chloropropane with sodium ethoxide.

21. Physical properties – mp / bp
How do the melting and boiling points of ethers compare to alcohols?
Why?

22. Physical properties - solubility
Why are ethers of low molecular mass soluble in water?

23. Chemical properties Flammable
Form peroxides on exposure to air / light (these are unstable and explosive) e.g. ethoxyethane peroxide