Suggest any limitations to the use of recrystallization as a purification method for a solid.

4 answers

What does Cypress have to do with a chemistry question?
thought it asked for school, why does it matter anyways
Thank you for responding.

The subject matters because we have many experts who troll this board looking for questions they can answer. Since we're all volunteers who have limited time, some experts only look at the questions that are clearly in their field.

I'm sorry -- but I can't help you. My specialties are elementary and middle school subjects plus social sciences.
Crystallization as a means to purify a compound fails when the resulting crystal formed is a cocrystal made up off your compound and an impurity. This may occur if the impurities present depict shapes that are complementary to those of the molecules that compose the desired crystal compound. In other words, if the impurity has hydrogen bonds that are complementary to those of the molecules in the crystal lattice then both molecules are said to have complementary shapes to each other. This complementary shape to each other (the molecules) could then result in the formation of a new co-crystal with the impurity as one of the components, which would ultimately mean that the impurities would be incorporated within the the crystal lattice of the “purified” compound. Therefore, crystallization should not be used as a means of purification if the impurities present consist of complementary shapes to that of your desired compounds.