A saturated vapour pressure of a liquid increases when the

The correct option is: "Temperature of a liquid increases." Saturated vapour pressure refers to the pressure of the vapour in equilibrium with its liquid form at a particular temperature. When the temperature of a liquid is increased, the kinetic energy of its molecules also increases, causing more molecules to escape from the liquid surface and enter the vapour phase. As a result, the concentration of vapour in the air above the liquid increases, leading to an increase in the pressure of the vapour. On the other hand, when the volume of the liquid is increased or decreased, the concentration of vapour in the air above the liquid remains the same, as long as the temperature remains constant. Therefore, the saturated vapour pressure does not change with a change in the volume of the liquid. Similarly, when the temperature of the liquid decreases, the kinetic energy of its molecules decreases, causing fewer molecules to escape from the liquid surface and enter the vapour phase. Therefore, the concentration of vapour in the air above the liquid decreases, leading to a decrease in the pressure of the vapour.