Question

After fully dissolving an impure compound in 100 mL of hot ether, the solution was cooled and put on ice, but no crystals formed. option as the next step to take in the recrystallization procedure in order to obtain pure crystalline material. O A. Remove 60% of the solution by pouring it from the flask. Reheat the solution, cool, and put on ice. O B. Add an additional 25 mL of ether to the solution while on ice. O C. Remove 60% of the solvent through evaporation in a hot water bath. Cool the solution and put on ice. O D. Perform a hot filtration on the solution, cool, and put on ice.

Answer 1

While recrystallization if no crystal formation can be seen than it is possible that the solvent added for dissolving an impure substance, we need to do heating of the solution, as if more amount of solvent is added for the dissolution is more than we have to boiloff some solvent and than cool it again. Hence option C. is correct.

Now, as we are not removing solution at all for recrystallization, hence option A, is incorrect.

Option B is also incorrect as, the solvent is already more, and in this option, they are adding more solvent.

In option D, Here ether is the solvent and it is very volatile, hence for this solvent, hot filtration is not good to use.

Hence, option C is correct.

hope this helps!