How to calculate the amount of heat released during the crystallization of a body with a melting point?
The amount of heat required to melt a certain mass of a substance taken at the melting (crystallization) temperature is described by the formula –
Q melt = λ * m, where λ is the specific heat of fusion.
In the process of melting (the transition of a substance from one state of aggregation to another, from solid to liquid), the temperature at which the substance melts remains unchanged.
The same picture is observed in the opposite process, when the substance “returns” from the liquid state of aggregation to the solid one. This process is called crystallization.
It occurs at the same temperature at which melting took place.
During the crystallization of the solidifying substance, its temperature also does not change.
During this time interval, the substance gives out the excess of its thermal energy, calculated using the same formula given above. Therefore, in order to calculate the amount of heat released during crystallization of a body (Q), it is necessary to know the specific heat and mass of the crystallizing body.