Explanation:

When glucose is added to the beaker of water, it dissolves in the water and forms a solution. This solution has a lower vapour pressure than pure water which means that fewer water molecules will evaporate from the solution and enter the vapour phase. However, the addition of glucose also increases the total number of molecules in the solution, which increases the collision rate of water molecules with glucose molecules. This leads to an increase in the rate of evaporation of water molecules from the surface of the beaker and hence, the rate at which water molecules leave the vapour increases.

Factors affecting the rate of evaporation:

Before understanding why the rate at which water molecules leave the vapour increases, we need to understand the factors that affect the rate of evaporation. These factors are:

1. Temperature: The rate of evaporation increases with an increase in temperature because at higher temperatures, the molecules have more kinetic energy and hence, more molecules can escape from the surface.

2. Surface area: The rate of evaporation increases with an increase in surface area because more molecules are exposed to the surface and can escape into the vapour phase.

3. Humidity: The rate of evaporation decreases with an increase in humidity because the air already has a high concentration of water vapour and hence, fewer water molecules can escape into the air.

4. Concentration of solute: The rate of evaporation decreases with an increase in the concentration of solute because the solute molecules occupy some of the surface area and hence, fewer water molecules can escape into the vapour phase.

How the addition of glucose affects the rate of evaporation:

Now, let's see how the addition of glucose affects the rate of evaporation of water molecules from the surface of the beaker. When glucose is added to the water, it dissolves and forms a solution. This solution has a lower vapour pressure than pure water because the glucose molecules take up some of the surface area and hence, fewer water molecules can escape into the vapour phase. This would lead to a decrease in the rate of evaporation of water molecules from the surface of the beaker.

However, the addition of glucose also increases the total number of molecules in the solution. This means that there are more water molecules available to evaporate and enter the vapour phase. The glucose molecules also increase the collision rate of water molecules with glucose molecules. This leads to an increase in the rate of evaporation of water molecules from the surface of the beaker and hence, the rate at which water molecules leave the vapour increases.

Conclusion:

In conclusion, the addition of glucose to the beaker of water in equilibrium with water vapour leads to an increase in the rate at which water molecules leave the vapour. This is because the glucose molecules increase the collision rate of water molecules with glucose molecules, which leads to an increase in the rate of evaporation of water molecules from the surface of the beaker.

The vapour pressure of solution will be less than the vapour pressure of pure solvent, so some vapour molecules will get condensed to maintain new equilibrium.