Question

Explain the process of melting and latent heat of fusion.

Answer 1

Hint: To understand the process of melting and latent heat of fusion, it is important to understand the properties of the substances like solid, liquid or gas. Then we will understand the process of change in physical state of any of these substances. It is explained by definitions and examples.

Complete step by step solution:
The molecules in the solid state are closely packed in comparison to liquid and gas state. The process of change in distance between the molecules of the substances at a particular temperature describes the process of melting and latent heat of fusion.

Process of melting: In this process, the heat is absorbed in the surroundings of the substance to increase the intermolecular distance between the molecules.

Latent Heat of fusion: It is the amount of heat energy, which is required to melt the unit mass of solid into liquid state. Its unit is joules or calories per mole or unit mass of the substance which is in the process of changing its state.

Example: Water is boiling on a certain temperature, and the melting point is 100℃ (from where water starts converting into vapors), so temperature remains same i.e. 100℃ until the last drop of water evaporates, because all the heat which is in water is carried away by the vapor molecules.

Note: Both the processes are related to the process of conversion of the state of substance, so it creates confusion sometimes. But melting point is the point or temperature from conversion starts and latent heat is the amount of heat.