Question

For the equilibrium, $H_{2}O\left(s\right)\iff H_{2}O\left(l\right)$, which of the following is true?

• A. The pressure changes do not affect the equilibrium.
• B. The amount of ice that melts is more, if the pressure on the system is increased.
• C. The amount of liquid that freezes is more, if the pressure on the system is increased.
• D. At low pressure, the nature of equilibrium changes to forward direction.

Answer 1

The correct option is B The amount of ice that melts is more, if the pressure on the system is increased.

We know that the volume of ice is more than that of water. So, when the ice melts, the volume decreases.
Hence, the change in volume is negative.

According to Le Chatelier's principle, if the pressure on the system is increased, the system will shrink the volume and try to attain equilibrium. It will move the reaction towards the side which leads to a decrease in volume. So, when pressure increases, volume decreases.

This shifts the equilibrium, $H_{2}O\left(s\right)\to H_{2}O\left(l\right)$ towards right.