MSN Home  |  My MSN  |  Hotmail
Sign in to Windows Live ID Web Search:   
go to MSNGroups 
Free Forum Hosting
 
Important Announcement Important Announcement
The MSN Groups service will close in February 2009. You can move your group to Multiply, MSN’s partner for online groups. Learn More
Chemistry Corner[email protected] 
  
What's New
  
  Welcome Page  
  About This Site  
  Message Boards  
  General  
  Inorganic  
  Organic  
  Pictures  
  Random  
  FOR ALL  
  Handy Symbols  
  Chemistry Humor  
    
  Documents  
  Chemistry Sites I  
  Chemistry Sites II  
  Chemistry Sites III  
  Organic Sites I  
  Organic Sites II  
  Analytical Sites I  
  Analytical Sites II  
  Lesson Plan Sites  
  Online Problems  
  Names & Formulas  
  Naming Exercises  
  Equations I  
  Equations II  
  Eq. Exercises I  
  Eq. Exercises II  
  The Mole I  
  The Mole II  
  Mole Exercises  
  Stoichiometry  
  Stoich. Exercises  
  More Communities  
  School's Out!  
  _________________  
  Site Map  
  
  
  Tools  
 
Inorganic : Input please
Choose another message board		  
     
Reply
 Message 1 of 3 in Discussion 
From: MSN NicknameZurconium2  (Original Message)Sent: 4/4/2006 11:42 PM
Steve,
 
Hello! Hope you had a good spring break.  I hope you can help with this problem...
 

In the reaction: A �?products, the initial concentration of A is 0.2643 M.  35 minutes later, the concentration of A is 0.1832 M.  What is the initial rate of reaction expressed in Ms-1?

 

I am stuck!!

 

Thanks.



First  Previous  2-3 of 3  Next  Last 
Reply
 Message 2 of 3 in Discussion 
From: MSN Nickname·Steve·Sent: 4/5/2006 5:27 AM
Hi again and thanks, guess it's back to chemistry again!
 
In your problem, first, use the integrated form of the first order rate law, ln[A]t = -kt + ln[A]o, to calculate the value of the rate constant k.  [A]t = 0.1832 M, t = 35 min = 2100 s, and [A]o = 0.2643 M.

Now plug k and the initial concentration (0.2643 M) into the first order rate law, Rate = k[A], to get the initial rate when [A] = 0.2643 M.  That should do it!
 

Steve

Reply
 Message 3 of 3 in Discussion 
From: MSN Nickname·Steve·Sent: 4/5/2006 5:46 AM
I just realized that the problem does not specifically state that the reaction is first-order, I just assumed so from the way the reaction was written, "A  -->  products".  To tell for sure if it's first order and not second order, we need a little more information such as additional time and concentration values.
 
Steve