The Purity and Purification of Solids Melting Point Lab
The point of this lab was to determine the eutectic point for the naphthalene biphenyl mixture, as well as determining the melting point of an unknown substance by comparing it with two known samples. Melting point is a temperature in which a substance changes from solid state to liquid state. Melting points are used to determine whether the given substance is pure or not. Substances that melt sharply, less than 1-2°C indicates pure substance. Melting point can also be used to identify an unknown substance, by comparing its melting point with known substances melting point. If the substances are the same, the mixture will have a sharp un-depressed melting point, while if the substances are different, the mixture will be impure, and its melting point will be broad and depressed. Eutectic point is the temperature in which a mixture to have a lower melting point than any other mixture composed of same substances in different proportions.
There are two parts to this experiment; the first part is to determine the eutectic point of naphthalene biphenyl mixture, and the second part is to determine the unknown substance, by comparing its melting point with two known samples and its melting points. In both cases, the melting points of the substances will be used to determining the eutectic point and the unknown compound.
The purpose of this experiment was to determine the eutectic point for the naphthalene biphenyl mixture, as well as determining the melting point of an unknown substance by comparing it with two known samples. We will be constructing a melting point diagram by using the melting point data obtained as a class. From the melting point diagram, the eutectic point of naphthalene and biphenyl mixture was determined as 50% naphthalene. The melting point of unknown D was compared with one of the mixtures. The melting point of unknown D was higher than 126 degrees,...
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