Consider the crystallization of sulfanilamide from 95% ethyl alcohol. if impure sulfanilamide is dissolved in the minimum amount of 95% ethyl alcohol at 40°c rather than 78°c (the boiling point of ethyl alcohol), how would this affect the percent recovery of pure sulfanilamide? explain your answer.

Crystallization is purification technique in which the substance containing the impurities  is dissolved in the solvent near its boiling point. The solution is then allowed to cool slowly. This result in crystallization of the dissolved solid whereas the impurities remain the the solution form. As a result, the substance is purified.

It is important to dissolve the substance in a solvent near its boiling point. This allows maximum dissolution of the substance and hence higher percent recovery of the solid.

When we dissolve sulfanilamide in ethyl alcohol at 40 C instead of its boiling point, less amount of sulfanilamide gets dissolved in ethyl alcohol . This happens because as the temperature decreases, the solubility of the solid also decreases.

This would result in lower percent recovery of sulfanilamide