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!

Ionic exchange

  1. Feb 19, 2013 #1
    1. The problem statement, all variables and given/known data

    10 mL solution of 0.5 M CrCl(OH2)52+ is allowed to aquate to Cr(OH2)63+. To determine an approximate rate of reaction, the amounts of CrCl(OH2)52+ and Cr(OH2)63+ present after a certain period of time are evaluated. This is done by pouring the solution on a cation exchange resin in the H+ form and then titrating the displaced H+ with base. If 80 mL of 0.15 M NaOH is required to neutralize the liberated H +, what was the concentration of CrCl(OH2)52+ and Cr(OH2)63+ in the solution?

    2. Relevant equations



    3. The attempt at a solution

    CrCl)OH2)5 +2

    V=10ml c=0.5M
    n=(0.01L)(0.5M)
    n=0.005mol

    NaOH

    V=80mL c=0.15M
    n=(0.15M)(80/1000)
    n=0.012mol

    Total volume=90mL
    c1v1=c2v2
    (0.5M)(10mL)=c2(90ml)
    c2=0.056M

    im not really sure if im doing this right, any help please :(
     
  2. jcsd
  3. Feb 20, 2013 #2

    Borek

    User Avatar

    Staff: Mentor

    I don't think you are doing it right, even if you have not wrote what you are doing and what c1 and c2 are.

    How many moles of H+ are liberated per each mole of CrCl(H2O)52+?

    How many moles of H+ are liberated per each mole of Cr(H2O)63+?

    If a mixture contains n1 moles of CrCl(H2O)52+ and n2 moles of Cr(H2O)63+, how many moles of H+ will be liberated? How many moles of NaOH will be needed to titrate the elute?

    And finally, what does n1+n2 equal to?

    This gives you two equations in two unknowns and finding the concentrations of both complexes shouldn't be difficult.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Ionic exchange
  1. Ionic bonds (Replies: 1)

  2. Ionic nomenclator (Replies: 3)

  3. Net ionic and Ionic (Replies: 1)

  4. Ionic equation (Replies: 0)

  5. Ionic Equilibrium (Replies: 2)

Loading...