rp10 questions to learn (3)

Question 1

Why do we heat up the dissolved aspirin in a water bath?

Answer 1

All in the reaction mixture will dissolve in this way

Question 2

Why do we ensure that the water bath is no hotter than 78oC?

Answer 2

Ethanol boils at 78 degrees celsius and so we want to prevent the solvent from evaporating.

Question 3

What steps are taken to ensure that the crude aspirin dissolves?

Answer 3

Break up the solid aspirin impurities as much as possible
Stirring to ensure we surround reaction mixture with as much ethanol as possible.

Question 4

Why is the hot mixture placed into cold water?

Answer 4

Cool the reaction mixture down
+ Gives a platform to recrystallise the crystals

Question 5

What is removed from the aspirin solution during filtration?

Answer 5

Water and soluble impurities