Question

In the first recrystallization, after the solid has been dissolved in warm acetone, the solution is allowed to cool slowly to room temperature. In an older procedure the warm solution was placed directly into an ice bath. How does this older procedure differ from a normal recrystallization and what might be the consequences?

Answer 1

The difference in the slow cooling of a warm solution and older sudden cooling (in to ice bath) of a warm solution for the process of recrystallization and its consequence is stated as follows:

In crystallization process if we use slow cooling then we can find bigger crystal than if we use sudden cooling. In sudden cooling process we find smaller and temporary crystal.

Also, while considering a saturated solution there is little amount of impurity. If we use quick cooling process then this non soluble impurity stick into the crystal and the crystal become defiled and impure. On the other hand if we use slow cooling then this impurity goes out of the crystal and crystals become more pure.