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Monday, January 24, 2011

our assignment. . . .

Chapter 3 : Reaction Kinetics




3.1 Chemical Kinetics


Reaction Rates : - Change in concentration of reactants (or products) as a function of time

 

3.2 How to Express Reaction Rate


=> Rate = d[A] 

                   dt

     change in concentration of A over a period, t when 
     [A] decrease with time, change of [A] is -ve.


=> Unit : mol/Ls @ M/s




3.3 Differential Rate Equation


     aA + bB ---------> cC + dD


     
   
     * Keep In Mind : 2A ----> B means by 2 mol of A 
        dissappear in each mole B formed.



3.4 Rate Law

    - expressing rate as function of reactant 
     concentration and temperature

   - given aA + bB ----------> cC + dD, so the rate law 
      is :
     



 

    - also called rate equation



 3.5 Rate Equation
 
k = rate constant



- proportionally constant for a given reaction and     
   temperature.
        
- does not change as reaction proceed.


3.6 Reaction Orders

  => Define how the rate affected by reactant 
        concentration

  => Always determine by experimentally

  => Order or reaction is no related to stoichiometry 
        ceofficent of reactant in balance chemical eqn.
     

  
    

          
           Example 1 :
      
             



         Example 2 :

         Find the overall order from rate equation below :
           
          
             
           


    ORDERS




       
     OVERALL REACTION ORDERS
  


    KEEP IN MIND =)

    


   
 3.7 Integrated Rate Law 

 Function of integrated rate law :

 * can estimate the period taken for x mol/L of 
   compound A to be used up            

  * we can know the concentration of compound A after
    the reaction in specific time


 



            RATE = k [A]

 
 


 







 





    





 






 



        

    KEEP IN MIND =)