Also, the water molecules are not changed when sugar is dissolved in water to form a sugar solution. We can easily get back the sugar by evaporation of water from the sugar solution. The evaporated water can then be condensed to recover the water also. Hence, it is a physical change and not a chemical change.
Answer: If the potential energy of the reaction system decreases, then kinetic energy in the surroundings increases and the temperature of the surroundings rises
