A melting point is a temperature at which the substance is at its maximum liquid temperature. This is the basic physical property of crystalline substances. However, the melting point is also used to describe the temperature at which the substance changes from a crystalline solid to a liquid.
The melting point of sodium thiosulfate pentahydrate is around 48 degC, or 321.4 K. This means that the substance is very soluble in water.
Sodium thiosulfate is a common chemical compound. It is used as a disinfectant, chlorine neutralizer, and as a germicide. In addition, it is used in the manufacturing of leather and in the tannic acid extraction of silver from ores. Also, it is used as a mordant in paper and textile industries.
Typical examples of using the melting point of sodium thiosulfate include supersaturation experiments. These experiments are designed to show students the concept of supercooling.
One of the most common methods for measuring the melting point of sodium thiosulfate is by measuring the enthalpy of melting. The enthalpy is measured in the same way that the enthalpy of fusion is measured. For example, Gronvold and Meisingset found that the enthalpy of melting for sodium thiosulfate was 209 J/g.
However, the melting point of sodium thiosulfate may be obtained using a variety of techniques. To measure the enthalpy of melting, one can use an adiabatic calorimeter. Or, it can be done by exposing the substance to a small flame for about twenty-five minutes.