Question

While performing a recrystallization, a chemist notices that a small amount of the sample will not dissolve, even after the recrystallization solution has been boiling for some time. Select the correct course of action.

A. Perform a gravity filtration with a stemless funnel.
B. Perform a gravity filtration with a long-stemmed funnel.
C. Isolate the insoluble material via filtration, grind it into a powder, and add it back to the recrystallization solution
D. Cool the recrystallization solution to room temperature and then heat it again to dissolve the insoluble material.

Answer 1

Answer: A. Perform a gravity filtration with a stemless funnel.

Explanation: Gravity filtration with a stemless funnel prevent blocking up the funnel. Undissolved sample may come out in the stem when the solution cools down thus will be blocking the funnel. Using stemless funnel prevent this problem.