Conclusion
In this experiment, we need to be careful when measuring the melting point of compounds because if we put too much of the sample into the capillary tube there would be poor heat transfer and if the compound is not a very fine powder, we would not get very good heat transfer. Mistakes can occur when measuring the melting point because there might be some king of changes in the compound such as sagging or shrinking and one can take it as the start of melting which actually is not. Another process that we must be aware of when taking the melting point of a compound is called sweating. Sweating is not melting. Sweating refers to process when we might have traces of moist due to not very well drying of the tubes.
All these possible errors can occur and this would lead us to wrong results.
OR
Within this lab we observed the characteristics of melting points and how they could be used to identify an unknown substance.
When we melted benzoic acid the melting point we had found was between 123-125 degrees celcius which is higher than what the literature had stated and when we had melted mandelic acid, we had observed it starting to melt earlier than the literature had stated although it did complete melting at the accepted temperature.
It was determined that for the unknown substance #14 the melting point had started at 153 degrees celcius and had completely melted at 155 degrees celcius. Given this range, we know that the unknown substance could be benzilic acid which has a melting point between 150-154 degrees celcius or adipic acid which has a melting point between 152-154 degrees celcius. Based on my results of melting the unknown compound with benzilic acid and then with adipic acid I am led to believe that unknown compound #14 was adipic acid. When melted together with adipic acid, the unknown had a narrower range of when it began to melt and when it completed melting as well as it's melting point had not been lowered due to an impurity as was the case of when the unknown had been mixed together with benzilic acid and had melted.
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