Question

9. Ex tra Credit: A mental model to represent the dissolution reaction MgSO4(s) → Mg2+(aq) + SO42-(aq). Draw a picture on a separate page that illustrates how heat is gained or lost at the level of atoms and molecules for the MgSO4 system. Consider question #1 when drawing the picture. a. b. Draw a second picture that illustrates heat gain or loss for the solution of NH&NOs c. Explain how your pictures explain heat gain or loss. Cuesta College San Luis Obispo Chemistry 201A Fall 2018

Answer 1

NS-a In MgSO4 Enthalpy change will be negative.Heat is lost .Heat require to break the force of attraction in MgSO4 molecule(DeltaH1) and Heat require to break the force of attraction in water molecules(Delat H2) will be less than heat release when Mg2+ and SO42- interact with water moleules(Delta H3).

ANS-b In NH4NO3 Enthalpy change will be Positive. Heat is gained. Heat require to break the force of attraction in NH4NO3 molecule (DeltaH1)and Heat require to break the force of attraction in water molecules(Delta H2) will be more than the heat release when NH4+ and NO3- interact with water moleules(DeltaH3).