Question

A process of recrystallization involves dissolving the solid inan appropriate solvent at an elevated temperature and allowing thecrystals to re-form on cooling. Residual amount of solvent isremoved by drying the crystals and therefore usually does notconsider to be an impurity, although if the crystals are not driedproperly the residual solvent will affect the melting pointmeasurements.
The choice of solvent is the most critical step in the process ofrecrystallization. Which of the following criteria should besatisfied while choosing a solvent for recrystallization?

Select one:

a. A compound to be purified should be completely soluble in areasonable amount of hot solvent.

b. A compound to be purified should be insoluble, nearlyinsoluble, or slightly soluble in cold solvent.

c. Impurities should be either insoluble in the solvent at alltemperatures so they can be filtered out or soluble in a coldsolvent staying in it while the desired compound willprecipitate.

d. The boiling point of the solvent should be low enough so theresidual amount of it will be readily removable from the crystalsof pure compound.

e. The boinling point of the solvent should generally be lowerthan the melting point of the desired compound so the compound willnot melt while heating the solvent giving the impression that ithas been dissolved.

f. The solvent should not react chemically with the compoundbeing purified.

g. All of these considerations are correct.