Physics 2011 JAMB Past Questions - Question 18: The phenomenon that shows that increase in pressure lowers the melting point can be observed in

Correct Answer

B

Explanation

The phenomenon you're referring to, where an increase in pressure lowers the melting point of a substance, is known as "pressure-induced melting" or "pressure-induced phase transition." This effect is particularly evident in certain materials, such as ice.

In the case of ice, increasing the pressure can cause it to melt at a lower temperature than it would at standard atmospheric pressure. This is due to the unique properties of water and its ice phases. Normally, when you apply pressure to a substance, you'd expect it to increase its melting point. However, water ice has a structure that is more stable at higher pressures, which means that at higher pressures, it can melt at lower temperatures.

This phenomenon is not limited to ice; it can also occur in other substances with unusual phase diagrams or under specific pressure-temperature conditions. The exact behavior may vary depending on the specific material and its phase diagram.

Keep in mind that pressure-induced melting is a complex phenomenon and is not observed in all materials. It typically occurs in substances with particular molecular or crystal structures that are sensitive to changes in pressure.