Question

What are the two main requirements for a recrystallization solvent? Briefly describe the outcome and conclusions of your solubility tests for your Week 5 unknown.

Answer 1

Two main requirements for a recrystallization solvent-

• The recrystallization solvent should not completely solublise the substance to be purified at RT(room temperature), but should be soluble on heating might be boiling point of solvent.

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• The solvent should be in such a way that it should not dissolve insoluble impurities even at the solvent’s boiling point. said impurities removed by simple filtration.

For a given unknown compounds -

Solubility Tests-

• first try dissolusion in lowest polar almost non polar either by Hexane, PET ether, then moderately DCM (dichloro metane) , Ethylacetate , MeOH, EtOH , H₂O if partial water soluble.
• then after puting the sample into solvents and heat the reaction mixture upto complete dissolusion , complete Filter it.
• drying i is s the most main problem take conical flask