The Purity and Purification of Solids

The Purity and Purification of Solids

Robert Musafiri

CH 337M Laboratory

Department of Chemistry

Portland State University, Portland OR

Abstract

We used the data that was collected from the class to create the melting point diagram of naphthalene and biphenyl.

Our unknown D was determined to be Succinic Acid by the mixed melting point method.

1. Introduction This experiment has two parts. The first part has for purpose to use the melting point to identity the purity of a substance and the second part has for purpose to use the melting point to determine an unknown substance.

2. Experimental section

All the chemicals used were obtained from the PSU chemistry stockroom and the procedures were found in the lab manual.

For part A of our experiment, we used Naphthalene and Biphenyl with different compositions. We had small sample of

100 % Naphthalene (N) 100 % Biphenyl (B) 30 % N, 70 % B 90 % N, 10 % B 50 % N, 50 % B 10 % N, 90 % B 70 % N, 30 % B

We placed a small amount of the 100% Naphthalene (N) 100% Biphenyl (B) sample into a glass capillary and gradually heat it up and record the temperature at which the substance starts the melting process and the temperature at which that process stops. An electrically heated Mel Temp device was used to record the temperatures.

We repeated the same procedure for our 10% N, 90% B sample.

We then calculated from mass percentage using the following equation: (N=naphthalene, B=biphenyl)

Mole%