During the process of melting and boiling, the temperature undergoes some interesting changes. Let’s first focus on melting, where a solid substance is heated and transforms into a liquid state. Initially, as heat is applied to the solid, the temperature starts to rise steadily. However, at a certain point, the temperature remains constant for a while. This plateau in temperature is referred to as the specific latent heat.
The reason behind this phenomenon lies in the energy required to break the bonds between the particles in the solid. In a solid substance, the particles are tightly packed and held together by strong intermolecular forces. These forces, commonly known as bonds, keep the particles in a fixed arrangement. When heat is applied, the particles gain energy and start to vibrate more vigorously. As a result, the temperature of the solid increases.
At the specific temperature known as the melting point, the particles in the solid have gained enough energy to overcome the intermolecular forces holding them together. This leads to the breaking of these bonds, and the solid starts to change into a liquid. However, during this phase transition, the energy supplied is utilized in breaking the bonds rather than increasing the temperature. Consequently, the temperature remains constant despite the continuous supply of heat.
Once all the bonds are broken and the solid has fully transformed into a liquid, the temperature starts to rise again. This increase in temperature occurs because now the heat energy is being used to increase the kinetic energy of the liquid particles. The kinetic energy determines the speed of the particles’ motion, and as it increases, the temperature rises correspondingly.
It is important to note that the specific latent heat is different for each substance and depends on the strength of the intermolecular forces. Substances with stronger bonds require more energy to break their bonds and thus have a higher specific latent heat.
To summarize the process of melting, the temperature initially rises as heat is applied, reaches a plateau during the phase transition where the specific latent heat is utilized to break the bonds, and finally rises again as the liquid particles gain more kinetic energy.
Similarly, during boiling, the temperature undergoes a similar pattern. Initially, the temperature rises steadily as heat is applied to the liquid. However, once the boiling point is reached, the temperature remains constant during the phase transition from liquid to gas. This plateau in temperature is again due to the specific latent heat, but this time it is called the latent heat of vaporization.
During boiling, the heat energy is used to overcome the intermolecular forces between the liquid particles, allowing them to escape into the gas phase. Once all the liquid has vaporized, the temperature starts to rise again as the gas particles gain more kinetic energy.
During the processes of melting and boiling, the temperature experiences plateaus known as specific latent heat or latent heat of vaporization. These plateaus occur because the supplied heat energy is utilized to break the bonds between particles in the solid or liquid, rather than increasing the temperature. Once all the bonds are broken and the substance has fully transformed, the temperature rises again as the particles gain more kinetic energy.