Hello, I've tried working out these three problems on my homework but I'm not sure how to start it. I looked in the book but it doesn't explain clearly and im getting confused. If anyone here knows how to work these problems please let me know. Thanks in advance for any help. It will be much appreciated. Question One - When the solid NH4NO3 is dissolved in water at 25 C, the temperature of the solution decreases. What is true about the signs of enthalpy (H) and (S) for this process? Question Two - When a liquid evaporates, which is true about the signs of the enthalpy and entropy changes? Question Three - A temperature change causes the volume of a solution to increase. This change will cause: a) the molarity and molality to increase b) the molarity and molality to decrease c) the molarity to inscrease but not change the molality d) the molarity to decrease but not change the molality e) neither the molarity nor molality to change Again. Thanks in advance for any help that is given.