EXPERIM ENT: " WH O HAS MY CO MPOUND? " Name _______________________________________ Instructor ____________________________________ Chem ____________ Section/Color ______________Date ________________________________________ Laboratory Questions These questions are to be completed and turned in with the Laboratory Report. POST-L AB QUESTIONS1. The contamination of a pure organic with an impurity affects the observed melting point onlyif the impurity dissolves to some extent in the liquid phase of the organic compound. Therefore, small granules of sand or broken glass (sand and glass have similar compositions and melt only at very high temperatures) will not reduce the melting point of a pure organic compound with which they might be mixed. In a sample containing small grains of sand, what would you observein the Mel-Temp apparatus when you melt the sample that would indicate to you that your sample contained an impurity? (How would the melted sample look different than the melted sample of a sample without the added contaminant?) 2.Use the melting point phase diagram in the lab manual to help answer this question.
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