Chemistry 212

posted by .

What is the solubility of RaSO4 in 0.1381M Na2SO4? Ksp = 4.3x10^-11?

  • Chemistry 212 -

    RaSO4 ==> Ra^+2 + SO4^-2

    Ksp = (Ra^+2)(SO4^-2).
    If you let S = solubility RaSO4, then
    Ra^+2 = S
    SO4^-2 = S from RaSO4 and 0.1381 M in Na2SO4 so a total of (S + 0.1381)
    Substitute those values into Ksp expression and solve for S.

  • Chemistry 212 -

    Ksp = [Ra^+2][SO4^-2]
    4.3x10^-11 = [x][x]
    x=6.56x10^-6

    6.56x10^-6 + .1381??

    is that how im suppose to do it?

  • Chemistry 212 -

    No.
    4.3 x 10^-11 = (x)(x+0.1381)
    solve for x.
    NOTE:
    If you solve the equation as I wrote it you will need to solve a quadratic. Those are usually easy to do with modern calculators; however, you CAN make a simplifying assumption. You make the assumption that x + 0.1381 = 0.1381 (that is, that x is so small in comparison to 0.1381 that when added it isn't different than 0.1381). The equation then would look like this.
    4.3 x 10^-11 = (x)(0.1381) and solve for x. When you finish, then look at x+0.1381 and see how far it is from 0.1381. If x is so small that x+0.1381 is just 0.1381, then the assumption is ok. If not, the assumption is not ok and you must solve the quadratic. I ALWAYS make the assumption first and solve the easy equation, then check at the end and see if the assumption is ok.

  • Chemistry 212 -

    thanks a bunch!

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    what is the molar solubility of lead sulfate in 1.0 X 10^-3 M Na2SO4?
  2. chem

    The Ksp of PbI2 is 8.7x10^-9. Find the solubility of lead(II) iodide on mol/L. a. 1.3x10^-3 b. 9.3x10^-9 c. 6.6x10^-5 d. 1.6x10^-3
  3. Chemistry

    Which of the following substances has the greatest solubility in water?
  4. Chemistry

    What is the concentration of ammonia in a solution that is .500 M NH4Cl and in which the solubility of Mg(OH)2 is 1.0x10^-3 M?
  5. chemistry

    Calculate the molar solubility of MX2, if the Ksp=3.3x10^-8 how can i solve this problem?
  6. chemistry

    Calculate the molar solubility of MX2, if the Ksp=3.3x10^-8 how can i solve this problem?
  7. chemistry

    Calculate the molar solubility of MX2, if the Ksp=3.3x10^-8 i already asked this but im confused about one of the steps. Ksp = (x)(2x)^2 = 4x^3 = 3.3X10^-8 x = solubility = 0.00202M. but i don't understand do i substitute the x in …
  8. chemistry

    what is the solubility of barium sulfate in a solution containing 0.050 M sodium selfate?
  9. HELPP !!

    Copper(I) ions in aqueous solution react with NH3 according to Cu^+ + 2NH3 --> Cu(NH3)2^+ Kf=6.3x10^10 Calculate the solubility (in g/L) of CuBr (Ksp=6.3x10^-9) in 0.81 M NH3.
  10. Chemistry

    What is the approximate ratio of the solubility of CaSO4 (Ksp = 2.4 x 10−5) in pure water to the solubility of CaSO4 in 0.10 M Na2SO4 at the same temperature?

More Similar Questions