Pressure affects change in melting point.
Pressure affects change in melting point.
Both boiling point and melting point of a substance increases with increase in pressure.
To explain it in simple way, if a gas is taken in a closed system, let its pressure be P1. So when we apply pressure P2 to that gas where P2 > P1, at a constant temperature (less than its critical temperature), it liquifies (as in case of LPG). It happens, as we know, because of the reduction in the volume for the same fixed mass of gas. Therefore, the molecules become more and more compact. Similarly if we consider solids and liquids on a smaller scale, we can assume that they have short range of intermolecular distance; whenever there is an increase in pressure on those molecules of that substance, (as per kinetic theory) the forces of attraction between molecules increases. Thus more amount of heat energy needs to be expended (can consider as latent heat) to seperate the molecules, under the influence of that pressure. We know that temperature of a substance is proportional to its heat energy and hence requires more temperature for the same amount of substance to get converted into other state of matter.
Both boiling point and melting point of a substance increases with increase in pressure.
To explain it in simple way, if a gas is taken in a closed system, let its pressure be P1. So when we apply pressure P2 to that gas where P2 > P1, at a constant temperature (less than its critical temperature), it liquifies (as in case of LPG). It happens, as we know, because of the reduction in the volume for the same fixed mass of gas. Therefore, the molecules become more and more compact. Similarly if we consider solids and liquids on a smaller scale, we can assume that they have short range of intermolecular distance; whenever there is an increase in pressure on those molecules of that substance, (as per kinetic theory) the forces of attraction between molecules increases. Thus more amount of heat energy needs to be expended (can consider as latent heat) to seperate the molecules, under the influence of that pressure. We know that temperature of a substance is proportional to its heat energy and hence requires more temperature for the same amount of substance to get converted into other state of matter.
