Question

If pressure is applied to the equilibrium of solid $\rightleftharpoons$ liquid. The melting point of the solid :

• A. will not change
• B. may increase or decrease depending upon the nature of solid
• C. will always increase
• D. will always decrease

Answer 1

The correct option is B may increase or decrease depending upon the nature of solid

If pressure is applied to the equilibrium of solid $\rightleftharpoons$ liquid. The melting point of the solid may increase or decrease depending upon the nature of solid.

As, $V\left(s\right)>V\left(l\right)$ for ice-water and $V\left(s\right)<V\left(l\right)$ for others.

For most substances, increasing the pressure when a system is in equilibrium between liquid and solid phases will increase the phase transition temperature. Water is one of a few special substances for which the pressure lowers the temperature of transition. The basic reason is that water actually expands when it goes from the liquid to solid phase.