1. II.3 Predicting Whether a Rx is Spontaneous or Not p. 43 - 49

2. Spontaneous a change that occurs by itself, without any help some rxs are spontaneous, others are not

3. Enthalpy H (heat) systems drive towards the lowest possible energy state endothermic rx = +H exothermic rx = -H

4. Entropy S possibility for disorder, the drive towards randomness increasing entropy = +S decreasing entropy = -S

5. There are 2 drives in any rx: the tendency for a rx to go to the side with MAXIMUM RANDOMNESS (MAX. ENTROPY) the tendency for a rx to go to the side with MINIMUM ENERGY (MIN. ENTHALPY)

6. Ex. showing an Increase S: gas formed from a solid gas formed from a solution # mol of gaseous product is greater than # mol of gaseous reactant when a solid dissolves in water

7. Ex. of Minimum Enthalpy: PE Time Exo favours products

8. Ex. of Minimum Enthalpy: PE Time Exo favours products PE Time Endo favours reactants

9. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic favours _______ (+) favours _______ (-) exothermic favours _______ (-) favours _______ (+) endothermic favours _______ (+) favours _______ (+) endothermic favours _______ (-) favours _______

10. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products (-) exothermic favours _______ (-) favours _______ (+) endothermic favours _______ (+) favours _______ (+) endothermic favours _______ (-) favours _______

11. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours _______ (-) favours _______ (+) endothermic favours _______ (+) favours _______ (+) endothermic favours _______ (-) favours _______

12. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours products (-) favours reactacts (+) endothermic favours _______ (+) favours _______ (+) endothermic favours _______ (-) favours _______

13. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours products (-) favours reactacts Spontaneous Rx goes to Equil. (+) endothermic favours _______ (+) favours _______ (+) endothermic favours _______ (-) favours _______

14. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours products (-) favours reactacts Spontaneous Rx goes to Equil. (+) endothermic favours reactants (+) favours products (+) endothermic favours _______ (-) favours _______

15. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours products (-) favours reactacts Spontaneous Rx goes to Equil. (+) endothermic favours reactants (+) favours products Spontaneous Rx goes to Equil. (+) endothermic favours _______ (-) favours _______

16. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours products (-) favours reactacts Spontaneous Rx goes to Equil. (+) endothermic favours reactants (+) favours products Spontaneous Rx goes to Equil. (+) endothermic favours reactants (-) favours reactants

17. The Probability of a Rx Occuring: HSSpontaneity (-) exothermic Favours products (+) favours products Spontaneous Rx goes 100% (-) exothermic favours products (-) favours reactacts Spontaneous Rx goes to Equil. (+) endothermic favours reactants (+) favours products Spontaneous Rx goes to Equil. (+) endothermic favours reactants (-) favours reactants Rx will NOT occur

18. Ex: 2NH 3(g) + 92 kJ N 2(g) + 3H 2(g) H favours___________ S favours___________ therefore the rx ________________

19. Ex: 2NH 3(g) + 92 kJ N 2(g) + 3H 2(g) H favours reactants S favours products therefore the rx ________________

20. Ex: 2NH 3(g) + 92 kJ N 2(g) + 3H 2(g) H favours reactants S favours products therefore the rx goes to equilibrium

21. BaCO 3(s) BaO (s) + CO 2(g) H=600kJ H favours___________ S favours___________ therefore the rx ________________

22. BaCO 3(s) BaO (s) + CO 2(g) H=600kJ H favours reactants S favours products therefore the rx ________________

23. BaCO 3(s) BaO (s) + CO 2(g) H=600kJ H favours reactants S favours products therefore the rx goes to equilibrium

24. 3H 2(g) + CO (g) CN 4(g) + H 2 O (g) H = -51 kJ H favours___________ S favours___________ therefore the rx ________________

25. 3H 2(g) + CO (g) CN 4(g) + H 2 O (g) H = -51 kJ H favours products S favours reactants therefore the rx ________________

26. 3H 2(g) + CO (g) CN 4(g) + H 2 O (g) H = -51 kJ H favours products S favours reactants therefore the rx goes to equilibrium

27. H 2 O (l) + heat H 2 O (g) H favours___________ S favours___________ therefore the rx ________________

28. H 2 O (l) + heat H 2 O (g) H favours reactants S favours products therefore the rx ________________

29. H 2 O (l) + heat H 2 O (g) H favours reactants S favours products therefore the rx goes to equilibrium

30. Do: 14 - 16