Question 2 • 26-27 - C - RUSD Chemistry in the Earth System
Dissolving a substance involves separating solute particles and separating solvent particles; both steps require energy, so they are endothermic. When solute and solvent particles attract and mix, energy is released, making that step exothermic. Thus, two steps are endothermic and one is exothermic, regardless of whether the overall enthalpy of solution is positive or negative.
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