Question

What is the effect of temperature on the vapour pressure of liquid?
A.Increase with decrease in temperature
B.Increase with increase in temperature
C.Depends upon the environment
D.None of the above

Answer 1

Hint: Vapour pressure is the tendency of the liquid at which it undergoes evaporation. The temperature at which the vapour pressure at the surface of liquid becomes equal to the pressure exerted by the atmosphere particle, it is the boiling point.

Complete answer: So, basically vapour pressure is the pressure at which equilibrium temperature is attained between the gaseous phase molecule and the liquid stage.
So, as the question is asking the relation between the vapour pressure and the temperature.
So, as when heat is supplied to the liquid, it gains kinetic energy and starts colliding with greater random speeds in the container and as a result of increase in kinetic energy, the vapour pressure also increases.
So, the vapour pressure is directly proportional to the temperature.
Hence, the increase in temperature will lead to increase in vapour pressure and vice-versa i.e. decrease in temperature will lead to decrease in vapour pressure.
So, the correct option is A.

Note:
There are few more factors that govern the vapour pressure of liquid in addition to the temperature. So, the vapour pressure of the liquid depends upon the concentration of the solute, and the intermolecular force of attraction between the particles and between the particle and the container and of course the temperature. One more additional fact that is often asked is the relation between the vapour pressure and the surface area of the container. So the answer is that the vapour pressure is independent of the surface area of the container. And also vapour pressure is independent of the humidity of the environment.