Question

Ice and liquid water are in equilibrium at $0^o$C and $1$ atm as shown given. Ice will be melted when:

• A. piston is moved upward at constant temperature
• B. more inert $He$ gas is added without moving the piston at a constant temperature
• C. temperature is decreased
• D. none of these

Answer 1

The correct option is B more inert $He$ gas is added without moving the piston at a constant temperature

${H_{2}O}_{\left(s\right)}\rightleftharpoons {H_{2}O}_{\left(l\right)}$

Ice and liquid water are in equilibrium at $0^{o}C$ and $1atm$. Applying pressures greater than $1atm$ ice will melt due to lowering of melting point of ice by increasing pressure.

(A) If piston is moved upward, pressure will decrease, this will not help melting of ice.

(B) If more inert $He$ gas is added without moving the piston at constant temperature, then pressure will increase. This will help to melt the ice.

(C) If temperature is decreased, this will not help.