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!

Molar Solubility Questions

  1. Aug 6, 2013 #1
    1. The problem statement, all variables and given/known data
    I have worked these two problems to the best of my knowledge and I keep getting the wrong answer (I'm not sure what the right answer is). Here are the questions:

    1. At a certain temperature the solubility of barium chromate (BaCrO4) is 1.9×10-5 mol/L. What is the Ksp of BaCrO4 at this temperature?
    2. What is the molar solubility of silver phosphate (Ag3PO4) in water? Ksp = 1.8×10-18.


    2. Relevant equations

    The relevant equations are Ksp=([products]/[reactants])

    3. The attempt at a solution
    For question 1: BaCrO4⇔Ba2+ + CrO42-
    Ksp=[Ba2+][CrO42-]/1 (since it is a solid)
    Ksp=[x][x]=x2
    Ksp=[1.9x10-5]2=3.61x10-10 = 3.6x10-10

    For question 2: Ag3PO4⇔3Ag+ + PO43-
    1.8x10-18 = ([Ag+]3[PO43-])/1
    1.8x10-18 = [3x]3[x]
    1.8x10-18 = [27x4] then divide both sides by 27
    6.6666667x10-20 = x4 then do the fourth root on both sides
    x = 1.6068568x10-5 = 1.6x10-5

    I would very much appreciate any insight into this. Thank you!
     
  2. jcsd
  3. Aug 6, 2013 #2
    Your approach looks fine to me unless you have done some calculation mistake.

    What are the correct answers?
     
  4. Aug 6, 2013 #3
    It is an online homework, like a quiz, that we are allowed multiple attempts on. It doesn't give me the correct answer. I'll email the prof. Thanks!
     
  5. Jan 4, 2017 #4
    where is this coming from??? [27x4]
     
  6. Jan 5, 2017 #5

    Borek

    User Avatar

    Staff: Mentor

    Which part of [itex](3x)^3x = 27x^4[/itex] is unclear to you? This is a pretty basic algebra.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Molar Solubility Questions
  1. Question: Solubility (Replies: 6)

  2. Solubility question (Replies: 1)

Loading...