A student performs a crystallization on an impure sample of biphenyl. The sample weighs 0.5 g and contains about 5% impurity. Based on his knowledge of solubility, the student decides to use benzene as the solvent. After crystallization, the crystals are dried and the final weight is found to be 0.02 g. Assume that all steps in the crystallization are performed correctly there are no spills, and the student lost very little solid on any glassware or in any of the transfers. Why is the recovery so low?
1 answer
Too much solvent (i.e., Benzene). You add the solvent drop wise and only enough until your compound dissolves.
2 answers