DETERMINING THE MELTING POINT OF A SOLID

We can determine the melting point of a solid by putting some of the dry solids into a capillary tube. Then the tube is to be attached to the bulb of a thermometer. The thermometer together with a stirrer are placed in a test tube of water and then heated gently. When the solid melts, record down the temperature.

The pure solid have sharper melting points. This means they melt within narrow temperature range less than 0.5 C. Solids which are impure do not have a sharp melting points. Therefore they melt over a wide temperature range.

We often used water bath to determine the melting point of a solid. An oil bath will be used if a water bath is not hot enough to melt solid which has a melting point above 90 degree Celsius.