To Recycrilstalise A Sample Of Benzoin Acid And To Measure The Melting Point Of Benzoin Acid

Question 1

Why is there sometimes no need to carry out a hot filtration?

Answer 1

Hot filtrations are not necessary if there are no insoluble impurities

Question 2

Advantage of suction filtration over gravity filtration

Answer 2

It is a lot faster

Question 3

How to verify that the recrystallisation benzoic acid was purer than the original sample

Answer 3

Compare melting points. Purer sample should have a higher melting point and a narrower range

Question 4

One way of maximising the yeild of the recrystallisation process

Answer 4

Use the minimum amount of hot water as a solvent

Question 5

Common use of benzoic acid

Answer 5

Food preservative

Question 6

Name an instrument technique that could have been used to identify benzoic acid based on low energy electromagnetic radiations

Answer 6

IR spectroscopy

Question 7

Describe how the melting points of impure benzoic acid and of the recystalilized benzoic
acid could be measured

Answer 7

A small sample is placed into a melting point tube (capillary tube) and placed on the melting point

block. A thermometer is placed into the melting point block. The block is heated using a bunsen
burner. The temperature range of melting is observed.