Week 05 - Instructor - General Chemistry II General CHEM...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
General Chemistry II General Chemistry II CHEM 152 Unit 2 CHEM 152 Unit 2 Week 5
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Week 5 Reading Assignment Chapter 14 – Sections 14.2 (dynamic equilibrium), 14.3  (equilibrium constant)
Background image of page 2
UA GenChem CHEMICAL CHEMICAL EQUILIBRIUM EQUILIBRIUM How far does the reaction go?  What is the final concentration of  reactants and products? We have seen that when the rate forward equals the rate  backwards in a chemical reaction, the system reaches a state of  equilibrium. But, These are the types of questions we now want to  answer.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Chemical Equilibrium Chemical Equilibrium If NO 2  is reddish brown and N 2 O 4  is colorless: What is happening here?  What properties are changing? What is happening over time? After a long time? Consider this reaction:
Background image of page 4
UA GenChem The final state depends on:  1) The chemical nature of the        reactants and products  2) The conditions of the system  (temperature,  pressure, volume). Get time progression Check silberberg N 2 O 4 e 2NO 2 Low T           Hi   T
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Analyzing Reaction Progress Product-or Reactant  Favored Process? If we consider the two possible chemical processes in this system:     k 1 = exp(-E a 1 /RT)    Rate forward = k 1 [A] A     k 2 = exp(-E a 2 /RT)       Rate reverse = k 2 [B] Reaction progress A B E a 1          E a 2 .
Background image of page 6
UA GenChem Analyzing Reaction Progress What happens with  Rate forward   and  Rate reverse   as a function of  time? When does the reaction “stop”?      k 1 =exp(-Ea 1 /RT)    Rate 1   A    k 2 =exp(-Ea 2 /RT)    Rate TWO   1 st  order   reactions                  in  OPPOSITE                           with  
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem Analyzing Reaction Progress     k 1 = exp(-E a 1 /RT)    Rate forward = k 1 [A] A     k 2 = exp(-E a 2 /RT)    Rate reverse = k 2 [B] The system reaches a state of  chemical equilibrium  when: Rate forward =Rate reverse  or k 1 [A]=k 2 [B] k 1 /k 2 =[B]/[A] = K eq  (Equilibrium Constant)   
Background image of page 8
UA GenChem Chemical Equilibrium Let’s try the following system: A 100 B Probability  B     60 %  A     30 % Analyze the time evolution  of this system How many particles of each  species do we have at  chemical equilibrium?
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UA GenChem 0.6     0 0.4 0.6 0.4   x  0.6  =  0.24     0.6  0.3  =  0.18 0.34 0.66 ? ?
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 41

Week 05 - Instructor - General Chemistry II General CHEM...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online