2. Heat of solution
Lattice Energy – energy required to completely separate one mole of a solid ionic compound into gaseous ions.

3. Heat of solution

4. Thermodynamics – the scientific study of the interconversion of heat and other kinds of energy

5. State function – properties determined by the state of the system, regardless of how that condition was achieved.

6. State function – properties determined by the state of the system, regardless of how that condition was achieved.

7. First law of thermodynamics
Energy can be converted from one form to another, but cannot be created or destroyed

8. Molecules possess two types of energy
Kinetic –
molecular movements (bends stretches displacement)
movement of electrons in the molecule
Potential –
attraction of e- and P+
repulsions of nuclei
interactions with other molecules (attractive forces)

9. Energy Transfer
It is not possible to measure all of the above interactions with much degree of certainty, but we can measure energy change in a chemical reaction
HCl + H2O  H3O+ + OH-
ΔE = Ef - Ei

10. Energy Transfer
ΔEsys + ΔEsurr = 0
ΔEsys = - ΔEsurr

11. Energy Transfer ΔE = q + w heat and work + q = endothermic
- q = exothermic
+ w = work done on the system from the surroundings
- w = work done on the surroundings by the system