A quality control technician performed a melting point experiment on the aspirin
ID: 861479 • Letter: A
Question
A quality control technician performed a melting point experiment on the aspirin made by some pharmaceutical company. He noted that the aspirin began to melt at 125 degree Celsius and was completely melted at 133 degree Celsius. He repeated the experiment two more times taking great care to watch the solid. The results were the same. The melting point of aspirin is given as 135 degree Celsius. Based on these results, did the quality technician allow the company to sell the product? Explain the answer
Explanation / Answer
An impurity causes the melting point to deviate from the standard. An impurity also causes the melting point to become a melting range. The melting point is not anymore sharp, but a range of values. The melting point the technician took of the sample of 'aspirin' was neither a sharp point it was a wide range of values and it the range was also a deviation from the standard 135 degrees Celsius. Conclusion, no I would have to say the technician didn't allow the company to sell the product as there is strong evidence that it contains impurities. These impurities may be potentially dangerous to health.
(((So basically, those are the two effects that impurities have on melting point of a compound. The impurities "defect" the crystal lattice of the compound. A pure compound is a structure of high molecular symmetry. An impurity is rather assymetrical, or is a poorly organized structure. If the impurites are present with the pure compound, the melting point will deviate because melting point is also dependent on the high symmetry and organization of molecular structures, just as the vapor pressure. This is the principle involved in Sublimation and Melting point determination.)))