Specific heat of solidification is the heat energy to be released for solidification of a liquid per kilogram of the substance!

## Melting and solidification

In the article on specific latent heat of fusion, it was explained in detail that when a solid is to be melted, energy is required to break the bonds so that the substance changes to the liquid phase. This energy is added to the substance as heat and is called heat of fusion. In the case of pure substances, the temperature remains constant during melting. Figure: Supply of heat of fusion during melting and dissipation of heat of solidification during freezing

If the liquid substance is to be solidified, then the heat previously added must be released so that the molecules can bind to each other again. In this case, the heat energy to be given off during the solidification of the liquid is called heat of solidification. Even while the heat of solidification is being released, the temperature remains constant. It only drops when the liquid substance has completely solidified. The temperature at which a substance solidifies corresponds to the melting point of the substance (also called solidification point).

For a more detailed explanation of the molecular processes that occur during solidification and the reason why the temperature remains constant, see article Why does the temperature remain constant during a change of state (phase transition)?

## Specific heat of fusion and solidification

Due to the conservation of energy, the amount of heat absorbed by a substance to melt (heat of fusion) is equal to the amount of heat released by the substance during solidification (heat of solidification). For this reason, the specific heat of solidification qs, as the ratio of the heat of solidification Qs and the solidifying mass ms, is as great as the specific heat of fusion qf.

\begin{align}
&\boxed{q_\text{s} = \frac{Q_\text{s}}{m_\text{s}}}~~~\text{where}~~~\boxed{q_\text{s} = q_\text{f}} \\[5px]
\end{align}