Download presentation

Presentation is loading. Please wait.

Published byCole Moser Modified over 4 years ago

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

Similar presentations

OK

Energy & Heat Energy – ability to produce heat Heat - energy in the process of flowing from a warmer object to a cooler object. In chemical reactions.

Energy & Heat Energy – ability to produce heat Heat - energy in the process of flowing from a warmer object to a cooler object. In chemical reactions.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on self development quotes Ppt on interest rate risk management Ppt on formation of company Ppt on hybrid solar lighting system Ppt on ideal gas laws E paper display ppt on tv Short ppt on rainwater harvesting Ppt on group development activities Ppt on preposition in hindi Ppt on nuclear energy in india