6E: Alcohols

Question 1

Reaction of alcohols with oxygen in air:
Product.

Answer 1

Carbon dioxide and water

Question 2

Describe the reaction:
Alcohol -> Carbon dioxide + Water

Answer 2

React with oxygen in air

Question 3

Reaction of alcohols with PCl₅:
Products,
Observation.

Answer 3

Chloroalkane, POCl₃ and HCl,
Steamy white fumes

Question 4

Describe the reaction:
Alcohol -> chloroalkane

Answer 4

React with PCl₅,
Produces POCl₃ and HCl,
Steamy white fumes.

Question 5

Describe the test for HCl _(g)

Answer 5

Hold a rod covered in concentrated ammonia near the fumes,
- produces dense white smoke

Question 6

Reaction of alcohols with potassium bromide:
Conditions,
Product.

Answer 6

50% concentrated sulfuric acid, heat under reflux,
Bromoalkane.

Question 7

Describe the reaction:
Alcohol -> bromoalkane

Answer 7

React with 50% concentrated sulfuric acid and potassium bromide,
Heat under reflux.

Question 8

Reaction of alcohols with red phosphorus and iodine:
Conditions,
Product,
Equation.

Answer 8

Warm conditions, damp phosphorus,
Iodoalkane,
3 Alcohol + PI₃ -> 3 Iodoalkane + H₃PO₃

Question 9

Describe the reaction:
Alcohol -> iodoalkane

Answer 9

React with damp red phosphorus and iodine,
Warm conditions.

Question 10

Reaction of primary alcohols with potassium dichromate(VI):
Conditions,
Colour change,
Products.

Answer 10

Acidified potassium dichromate(VI),
Orange -> green,

Partial oxidation:
Distill immediately,
Aldehyde.

Complete oxidation:
Heat under reflux,
Carboxylic acid.

Question 11

Describe the reaction:
Alcohol -> aldehyde

Answer 11

Primary alcohol reacts with acidified potassium dichromate(VI),
Distill immediately.
Colour change orange -> green

Question 12

Describe the reaction:
Alcohol -> carboxylic acid

Answer 12

Primary alcohol reacts with acidified potassium dichromate(VI),
Heat under reflux.
Colour change orange -> green

Question 13

Reaction of secondary alcohols with potassium dichromate(VI):
Conditions,
Colour change,
Product.

Answer 13

Acidified potassium dichromate(VI), heat under reflux,
Orange -> green,
Ketone.

Question 14

Describe the reaction:
Alcohol -> ketone

Answer 14

Secondary alcohol reacts with acidified potassium dichromate(VI),
Heat under reflux.
Colour change orange -> green

Question 15

Reaction of tertiary alcohols with potassium dichromate(VI):
Conditions,
Colour change,
Product.

Answer 15

Resists oxidation, no reaction.
Stays orange

Question 16

Describe the test for aldehydes.

Answer 16

Warm with Fehling’s solution,
- Blue solution -> Red precipitate

Question 17

Reaction of alcohols with phosphoric acid:
Conditions,
Product.

Answer 17

Concentrated acid, heat under reflux,
Alkene.

Question 18

Describe the reaction:
Alcohol -> alkene

Answer 18

React with concentrated phosphoric acid,
Heat under reflux.

Question 19

What is the purpose of anti-bumping granules?

Answer 19

Encourages the formation of small bubbles, which allows for smooth boiling.