Question

For an equilibrium $H_{2}O (s)\rightleftharpoons H_{2}O (l)$ which of the following statement is true:

• A. the pressure changes do not affect the equilibrium
• B. more of ice melts if pressure on the system is increased
• C. more of liquid freezes if pressure on the system is increase
• D. the pressure changes may increase or decrease the degree of advancement of the reaction depending upon the temperature of the system

Answer 1

Answer: (B)

For an equilibrium $H _{2} O ( s ) \rightleftharpoons H _{2} O (\ell)$, the statement $B$ is true.
According to Le chatelier's principle, when pressure is applied, the equilibrium will shift in a direction in which there is decrease in volume.
At the melting point, the density of ice is lower than the density of water. This means that the volume of ice is larger than the volume of water at the melting point.
Hence, ice contracts on melting.