Question

jab doodh hum ubhal tei hai toh hum dekhte hain ki jhoon he vapour pressure increase hota hai toh hum usmai spoon dalte hai toh us ka vp down hota hai aisa kyun​

Answer 1

Because of “impurities”. Now these impurities can be anything. Ions, colloids, salts, etc. As long as it actually reduces the mole fraction of the pure solvent in the solution. The phenomenon might be caused by any of possible actions of the solutes such as intermolecular interactions with water molecules that could keep if from vaporizing or taking up some of the energy of the system at constant temperature which would result to a lower kinetic energy for water molecules in order for them to vaporize.