Question

1a) Can aspirin be recrystallized from any non-polar solvent?
1b) Why is it important to add the minimum amount of solvent during recrystallization?
A. Because the solution has to be heated until it crystallizes
B. Because the solution could become oversaturated
C. Because it will be too easy to crystallize compound
1c) Synthesis of Aspirin is an example of a(an) _____ reaction:
A. Acidification
B. Acylation
C. Basification
D. Esterification
E.  Etherification

Answer 1

1a) The reason why aspirin cannot be purified from any non-polar solvent is that the prime impurity during the synthesis of aspirin (2-acetyl salicyclic acid) is salicyclic acid. It is very diffcult to get rid of salicyclic acid (very-polar) with a non-polar solvent (beacuse of the poor hydrophobic interaction of non-polar solvents with polar COOH groups of salicyclic acid). Thats why we need ethanol for the recrystallization of aspirin.

1b) B. Because the solution could become oversaturated

1c) B. Acylation [Introduction of COCH3 group is called acylation or acetylation. 2-acetyl salicyclic acid (Aspirin) is synthesisze by the acylation of salicyclic acid]