Organic Chemistry Lab/ Chem 234
Lab 2: Melting Points
Purpose: To determine the purity of a substance using melting point as physical property. We must also learn how to identify an unknown compound using its melting point. We got to identify an unknown compound using mixture melting point and finally we must learn to obtain an accurate melting point using Mel-Temp apparatus.
Procedure: Set voltage to obtain the desired heating rate at the anticipated melting point range. The voltage control controls the rate of heating and not the temperature. The higher the setting, the faster the temperature rise.
Obtain a sample or prepare a sample by packing capillary tube 3-4 mm high with thoroughly dried, finely powdered, densely packed sample. Larger, loose samples will heat unevenly. Insert the loaded MP tube in one of the three channels in the opening at the top of the unit. Then insert thermometer into the thermometer well of instrument. Switch the power on making sure that apparatus is plugged in. Set the power according rate chart. Then observe samples but turn the voltage control to get a 2 degree Celcius per min rise when within 20 degrees Celcius of the melting range. We will do a set of trials for individual solutions for MP and combos of MP which is demonstrated through the chart on Mel-Temp melting point apparatus.
Experiment: Three trials
1. Individual solutions high temperature of 164-168 grados
The chart above gives the accurate data from the theoretical .
2. Combos solutions 164-168 degrees
Hypothesis: I believe that the melting points each individual to combo makes a less need for increase of temperature.
Data Analysis: If we look at the two charts and compare and contrast. There were first of all three trials given in the individual solutions chart. The three trials gave the same results. The ideal data was off for Urea by one point and cholesterol that was off by 2...