3) The melting point range of an unknown substance was determined to be 120-180 degree celcius. what can you tell about the purity of the unknown
Pure substances have a melting point range of 0.5-2 degrees C. So this sample must be quite impure.
To determine the purity of an unknown substance based on its melting point range, you would typically compare it to the expected or known melting point range of the pure substance. Without this information, it is difficult to accurately assess the purity of the unknown substance.
However, here are a few things you can consider:
1. The broader the melting point range, the more impure the substance is likely to be. In this case, the wide range of 120-180 degrees Celsius suggests the presence of impurities.
2. If the unknown substance has a melting point within the expected range for a known pure substance, it indicates that the substance is likely relatively pure.
3. If the unknown substance has a melting point lower or higher than expected, it could indicate the presence of impurities or a different compound altogether.
It is important to note that these observations can only provide general hints about the purity of the substance. A more accurate assessment would involve comparing the results to the known characteristics of pure substances or conducting further tests, such as spectroscopy or chromatography.