Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Rate law accuracy question?

  1. Apr 1, 2010 #1
    An experiment was done by me to determine the rate law of a reactant. If the reaction occurred faster(ex. by just stirring reactants), would the accuracy of rate law calculated increase? If it doesn't increase accuracy, then what is the point of stirring/swirling the reactants?

    I think that the accuracy would increase, because the rate law is most accurate for the initial concentrations at an specified temperature, and this changes more throughout a longer experiment, than a shorter one. So a faster experimental rate of reaction would increase the accuracy. Need some confirmation. Thanks.
     
  2. jcsd
  3. Apr 1, 2010 #2
    The rate laws using concentrations assume that the activity of the reactants are approximately equal to their concentrations, which is a fair assumption at low concentrations and temperature.

    Regarding your question about stirring, it might be useful to have the rectants uniformly spread throughout the container.
     
  4. Apr 1, 2010 #3
    Right, i don't understand why it needs to be uniform.
     
  5. Apr 1, 2010 #4
    In which situation do you think the reaction A+B->C will proceed faster, given the rate law r=k[A]. Remember that the rate law applies only locally.

    1) A and B uniformly distributed throughout the container.

    2) A on the bottom and B on the top, with smaller region in between where they are mixed.
     
  6. Apr 1, 2010 #5
    If the concentrations of the reactants vary at different points in the solution, then the reaction rate will also not be the same at all points in the solution.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Rate law accuracy question?
  1. Rate law equation (Replies: 12)

Loading...