1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Reaction rates

  1. Aug 12, 2014 #1
    1. The problem statement, all variables and given/known data

    Peroxydisulfate ion reacts with the iodide anion according to reaction 1:

    S2O82- + 3 I-⇔ 2 SO42- + I3-

    The amount of I3- formed can be determined by adding a known amount of SsO32- and allowing it to react according to reaction 2:

    2 S2O32- + I3- ⇔ S4O62- + 3I-

    If starch is added, any excess I3- will react to form a blue-black I2 complex. The formation of this complex indicates the completion of reaction 2. The rate of reaction 1 can be determined by the following equation where t is the elapsed time from the addition of the last component to the formation of the blue-black starch, I2 complex.

    rate = 1/2 [S2O32-]/t

    (1) what would happen to the time and the rate in equation 1, if more S2O32- were added, and all other conditions remained the same?

    2. Relevant equations

    3. The attempt at a solution

    The thiosulfate ion only applies to reaction 1, therefore, I assumed that the time would be constant and the rate would increase; however, I need help understanding my initial rationale. Thanks!
  2. jcsd
  3. Aug 20, 2014 #2
    I'm sorry you are not generating any responses at the moment. Is there any additional information you can share with us? Any new findings?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted