Chapter 16 - Organic Synthesis

Question 1

Describe the practical technique: reflux

Answer 1

A technique used for boiling volatile/flammable reactants/products over a prolonged period of time
Uses a vertical condenser - prevents loss of reactants/products as gaseous vapours
Any vapour formed is condensed back to a liquid and returned to the pear-shaped flask
ANTI-BUMPING GRANULES are required to prevent mixture from boiling

Question 2

Describe the practical technique: distillation

Answer 2

This technique relies on the fact that in a mixture of miscible liquids, each component has its own unique boiling point

Question 3

What are some key requirements for a distillation reaction to take place and avoid error?

Answer 3

The bulb of the thermometer must be positioned in line with the condenser to ensure an accurate reading of the boiling point of each liquid as it is collected
The water supply must be connected as shown to make sure that the condenser is completely full of cold water

Question 4

Describe the practical technique: redistillation

Answer 4

Occasionally some organic liquids have boiling point that are relatively close together so your prepared sample may still contain organic impurities
A second distillation will need to be carried out

Question 5

What does a narrow boiling point range tell us?

Answer 5

The purer the product

Question 6

Describe the practical technique: separating funnel

Answer 6

This technique is used to purify an organic product after it has been synthesised
The organic product will form a separate layer to any aq liquid present
The denser liquid will form the lower layer