Question

1.Under what circumstance would you use seed crystals?

2.What functional group is a petroleum ether?

3.What two factors influence the formation of crystals?

4.The presence of impurity will ______________ and ________________ the melting point range.

(raise or lower)              (broaden or narrow)

5. After recrystallization, an amateur chemist noticed that he/she lost over 50% of the product upon vacuum filtration. What do you suggest the chemist should do to recover the rest of the compound?  

6. Why should a hot recrystallization solution be filtered by gravity rather than by vacuum filtration?

Answer 1