Alcohols

Question 1

What is the functional group?

Answer 1

Hydroxyl group OH

Question 2

What are properties of alcohols?

Answer 2

Less volatile, increased melting point and solubility compared to alkanes.
As they have a polar OH group, they are water soluble as they form hydrogen bonds. As chain length increases, solubility decreases.

Question 3

What is the trend with boiling point?

Answer 3

As chain length increases, so does boiling point as more London forces are present with more contact points.

Question 4

How are alcohols classified?

Answer 4

Primary - 1/0 carbons bonded to the C with the OH
Secondary
Tertiary

Question 5

How are alcohols combusted?

Answer 5

Completely as they have 1 oxygen already.

Question 6

What substitution reactions do alcohols undergo?

Answer 6

With hydrogen halides to form haloalkanes. Heated under reflux with sulfuric acid catalyst and sodium halide.

Question 7

Do tertiary alcohols oxidise?

Answer 7

No

Question 8

How are alcohols dehydrated?

Answer 8

Elimination reaction as water is removed. Heated under reflux with acid catalyst to form an alkene.

Question 9

How are primary alcohols oxidised?

Answer 9

Aldehydes under distillation (to prevent further reactions)
Carboxylic acids under reflux

Question 10

What is needed for an alcohol to oxidise?

Answer 10

K2Cr2O7 in H2SO4 - oxidising agent.

Colour change of orange to green as it is reduced.

Question 11

How are secondary alcohols oxidised?

Answer 11

Ketones under reflux