Question

Why is it important to use only the minimal amt of hot solventneeded to achieve a recrystallization?
What would be the effect of using too much solvent while dissolvinga solid for recrystallization?

Answer 1

crystallization works on the principle that the capacity of asolvent to dissolve a solute increases with temp and decreases withdecrease in the temp of the solvent. so first we dissolve thesolute in the hot solvent and then we let it cool down. now whenthe temp decreases then the solvent will not be able to hold thedissolved solute in it and some of the solute will crystallize aswe further cool down the solvent, its ability to dissolve thesolute decreases and so some more amount of solute crystallizes. Sobased upon these concepts
minimal amount of solvent is used to achieve maximum amount ofcrystallization when the solvent cools down
if we use too much solvent then even when the solvent cools down itcould still hold the solute so crystallization will not take placeor just a little crystallization will take place leading to loss ofmaterial