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: Diverse Ion effect and Activity coefficients problem

  1. Oct 12, 2007 #1
    The question:

    How many grams of Ba(IO3)2 can be dissolved in 700mL of a 0.100M KIO3 solution at 25C? use activity coefficients for this. (Ksp of Ba(IO3)2 =1.57E-9)

    my answer:

    I used this equation: Ksp = (concentration) * (activity coefficient)

    well i found out that my ionic strength of KIO3 is 0.100M and from a chart, i found the respective activity coeff for Ba2+ and IO3-.
    Ba2+ ---> 0.38
    IO3^- ----> 0.775

    Ba(IO3)2 <----> Ba2+ + 2IO3^-
    I 0 x 0.100M
    C +x +2x
    E x 0.100M+2x

    using the equation above,
    Ksp = [Ba2+]*(activity coeff of Ba) * [IO3^-]^2 * (activity coeff of IO3^-)^2
    1.57E-9 = (x)(0.38) * (0.100+2x)^2 * (0.775)^2

    so i solve for X and that would be the concentration of Ba(IO3)2 in mol/L

    BUT, to solve for X, i found it complicated because there would be 3 solutions for X aren't there?? since it's X^3...... so i am confused on what to do.

    help appreciated, Thanks.
  2. jcsd
  3. Oct 12, 2007 #2
    there above numbers below the balanced equation is supposed to be an ICE table
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook