Question on recrystallisation
My A2 text book:
-dissolve theimure solid in aminimum of hot solvent
-remove any undissolved impurities by filtering the hot solution through a fluted filter paper using a warmed stemless funnel , into a conical flask.
-allow the solution to cool
-Filter the mixture of the pure solid and the solvent under reduced pressure, using a buchner funnel
Collect the solid on the filter paper and discard the filtrate which contains the soluble impurities
-Wash the solid on the filter paper and leave the solid to dry
-carefully remove the pure solid from the filter paper
Past Paper Question: Organic solids are often purified by recrystallisation.This technique waorks on the basis that...
Answer:the cooled solution is saturated with the desired material but not with the impurities
What i don't understand:My text book says that the desired compound is soluble in the hot solution bot not in the cooled solution . So how can the desired material be saturated in the cool solution?
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