Question

When pressure increases , what happens to -
1. melting point
2. freezing point
When pressure decreases , what happens to -
1. melting point
​2. freezing point

Answer 1

Melting point increases with increase in pressure as the phase transition equilibrium between the solid and liquid temperature increases. Freezing point decreases with increase in pressure as the water expands during freezing.
The reverse is the case of decrease of pressure. That is decreasing pressure decreases the melting point and increases the freezing.