Chemistry (urgent)

posted by .

Hi, I have a few chemistry problems that I'm having trouble solving. I put my attempted solutions after the problems in *'s. There was one problem I had no idea how to solve.

What concentration of silver chromate (Ksp = 9.0 x 10-12) will dissolve to make a saturated solution in water?

*For this one the formula is Ag2CrO4, which is [Ag]^2[CrO4]. I plugged x in for CrO4, so x^3 is equal to Ksp. I then got that x = 2.0e-4. However, that x is for CrO4, not for silver chromate. Is the answer for silver chromate just the Ksp value?*

What concentration of silver chromate (Ksp = 9.0 x 10-12) will dissolve in 500. mL of 0.01 M aqueous silver nitrate?

A saturated solution of CaSO4(aq) is made in a beaker until there is excess calcium sulfate resting at the bottom. Then solid potassium sulfate is added. Which of the following is true? (The Ksp for potassium sulfate is larger than the Ksp for calcium sulfate)
a. More calcium sulfate will start to precipitate out of solution
b. More calcium sulfate will start to dissolve in solution

*I know that when a smaller Ksp is added to a bigger Ksp it precipitates out of solution. Is that the same in the reverse?*

  • Chemistry (urgent) -

    Ag2CrO4 ==> 2Ag + CrO4^-2

    Ksp = (Ag^+)^2(CrO4^-2)
    What you do is let S = solubility of Ag2CrO4 in molarity. Then S is concn CrO4 and 2S = concn
    (2S)^2(S) = Ksp
    4S^3 = Ksp
    Solve for S. 2S will be Ag^+, S will be Ag2CrO4 and S will be CrO4^-2.

    #2. Here you have two equilibria.
    Ag2CrO4 ==> 2Ag^+ + CrO4^-2
    Ksp = (Ag^+)^2(CrO4^-2)

    And AgNO3 ==> Ag^+ + NO3^-
    AgNO3 is completely soluble BUT it contributes Ag^+. So if
    S = solubility Ag2CrO4, then S = CrO4^-2, 2S+0.01 = Ag^+. Plug these into Ksp for Ag2CrO4. (This is called a common ion problem and the common ion in this problem is the Ag^+. It's another example of Le Chatelier's Principle; adding AgNO3 forces the solubility to the left in the reaction and makes it more insoluble. In most cases, 2S + 0.01 = 0.01; i.e., 2S is small and contributes only slightly to the total Ag^+ and it makes it easier to solve the equation. So you end up with
    9.0 x 10^-12 = (0.01)^2(S) and solve for S which is CrO4 and Ag2CrO4. You will see that the solubility is much less in this problem than in the first problem solved.

    #3. I really hope no one is trying to tell you that K2SO4 has a solubility product. It doesn't. Not even close! This is a case of common ion, also. Here is how it works.
    CaSO4(s) ==> Ca^+2 + SO4^-2
    Ksp = (Ca^+2)(SO4^-2).

    K2SO4 ==> 2K^+ + SO4 (completely soluble).

    The SO4^-2 is the common ion. By Le Chatelier's principle adding sulfate (by way of K2SO4) forces the CaSO4 equilibrium to the left which means that CaSO4 is LESS soluble with K2SO4 added than when it isn't added. Therefore, some of the CaSO4 in solution will ppt. Talk of Ksp for K2SO4 has nothing to do with it.

  • Chemistry (urgent) -

    thank you so much!! I got a 100 on the test I was studying for!

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Algebra

    I have some problems that I am having trouble with and I have some that need checking please. Thanks! Solve the equation. 4. (x+7/4)=2(x-1/6) Find all the value(s) of x that make thedenominator(s) zero. Then solve the equation. 6. …
  2. Science

    Dunbar, South Africa identify at least two serious environmental problems, such as soil degradation, air or water pollution, pesticide misuse, overpopulation, wildlife extinction or threatened biodiversity, and deforestation, that …
  3. statistics

    in a classic study of problem solving, katona demonstrated that people whoa re required to figure out a problem on their own will learn more than people who are given the solution. One group of participants is presented with a series …
  4. Math

    I am having problems understanding how to solve problems like the following: a2 + b2 = c2 Please help me where I can understand solving problems such as the one above.
  5. Chemistry

    Hi, I have a few chemistry problems that I'm having trouble solving. I put my attempted solutions after the problems in *'s. There was one problem I had no idea how to solve. What concentration of silver chromate (Ksp = 9.0 x 10-12) …
  6. math

    So I've been having trouble solving some problems. Mainly problems that look like this 5-(t+3)=-1+2(t-3) what causes problems is the 5- part. I asked my teacher for help, and he gave me a hint, which is to distribute a -1 like 5+(-1)(t)+(-1)(3) …
  7. math

    I'm working on some review problems in Math and having trouble on the critical thinking one. The question says is it possible for 2 numbers to have the same LCM and GCF?
  8. Physics

    Please help!!! Physics test!? I have a physics test tomorrow on projectile motion, and I don't feel ready for it. I'm having trouble in the class and I need to ace this test. The problem is I get confused when I get a problem. I don't
  9. Calculus

    I am having trouble solving this problem: "Find where the tangent line is horizontal for r=1+cos(theta)" I would really appreciate the feedback, I'd like to know how to go about solving problems like these. Thank you!
  10. Chemistry URGENT

    I am having a hard time understanding how to calculate pH. my textbook states that that pH =-log[H^+]. I have two questions that asks: What is the H^+ concentration in an acid with of pH 4.6?

More Similar Questions