Alcohols

Question 1

Physical Properties of Alcohols

Answer 1

● hydrogen bonding (H-bonding) between O-H groups influences properties (less volatile)
● simple alcohols are liquid at room temperature
● less volatile that the equivalent hydrocarbon (i.e. higher boiling point range)
● smaller alcohols with up to 5 carbons are soluble in water
● alcohols are weakly acidic

Question 2

Chemical Properties of Alcohols

Answer 2

● alcohols are polar molecules
● alcohols possess a reactive OH group
combustion
substitution reactions (reaction with halides)
elimination reactions (dehydration)
ester formation (with carboxylic acids)

Question 3

Reactions of Alcohols

Answer 3

● combustion
● burns in air with a colourless flame
● Biofuels: methanol and ethanol are common fuels, and fuel additives

Question 3

Name the Substitution Reaction of Alcohols
&
examples

Answer 3

● synthesis of alkyl halides (haloalkanes)
examples:
1. Reaction with PCl5 (phosphorus pentachloride)
2. Reaction with PBr3 (phosphorus tribromide)
3. Reaction with SOCl2 (thionyl chloride)

Question 3

Elimination Reactions of Alcohols

Answer 3

● dehydration (removal of water)
● alkene synthesis