Which of the Following is an Endothermic Process (i) Dilution of Sulphuric Acid (ii) Sublimation of Dry Ice (iii) Condensation of Water Vapors (iv) Evaporation of Water

Answer: (ii) sublimation of dry ice 

Explanation: Sublimation of dry ice is a straight phase transition from a solid to a gas without going through a liquid state intermediate. This requires additional energy, hence, it is an endothermic reaction.