Why is vapour pressure of solution of glucose in water is lower than that of water?

Answer:

The vapour pressure of pure solvent decrease when a non- volatile solute is added to the solvent this is because on adding the solute, a fewer number of water molecules are present at the surface which can evaporate as some of the surface area is occupied by non- volatile solute molecules thereby decreasing the vapour pressure of the solution thus the vapour pressure of the solution of the glucose in water lower than that of water.