4.2.1 alcohols

Question 1

distillation of primary alcohol

Answer 1

Primary alcohol > aldehyde

potassium dichromate (VI) solution and dilute H2SO4

Warm gently and distil out the aldehyde as it forms

Orange dichromate ion (Cr2O7 2-) reduces to green Cr3+ ion

Question 2

Reflux primary alcohol

Answer 2

Primary alcohol > carboxylic acid

Reagent: potassium dichromate (VI) solution and dilute H2SO4

Conditions: use excess dichromate, heat under reflux

Orange dichromate ion > green Cr3+ ion

+ H2O, 2 [O]

Question 3

Reflux of secondary alcohol

Answer 3

Secondary alcohol > ketone

Potassium dichromate (VI) and dilute H2SO4

Heat under reflux

Orange dichromate to green Cr3+ Ion

Question 4

Alcohol and dehydrating agents

Answer 4

Alcohol > alkene

Concentration sulfuric or phosphoric acid
- acts as dehydrating agent

Conditions : warm (under reflux)

Type of reaction: acid catalysed elimination

Question 5

Alcohol to haloalkane

Answer 5

Concentrated sulfuric acid and sodium halide