a) A weak acid, HX, is 1.3% ionized in .20 M solution. What percent of HX is ionized in a .030 M solution? b) Does the percent ionization increase or decrease upon dilution? c) Does the H3O+ concentration of the above weak acid increase or decrease?

asked by TS
  1. Please help, struggling like crazy.

    posted by TS
  2. HX <-> H+ + X-

    Concentration = mol/vol
    Since we only know mol and not concentration, we can just use mol since it is directly proportional to concentration
    HX H+ X-
    I 0.2 0 0
    C -y +y +y
    E 0.2-y y y

    Since y is very small(weak acid) Equilibrium mol for HX is 0.2

    Ionization % = [H+]eq/[HX]i *100%
    For 0.2M, [H+] = 1.3% / 100% * 0.2= 2.6*10^-5
    y=2.6*10^-5 M

    Now we can calculate Ka of HX
    Ka = [H+][X-] / [HX]

    ICE table for 0.03M
    HX H+ X-
    I 0.03 0 0
    C -z +z +z
    E 0.03-z z z
    (Once again, HX at equi = 0.03)

    Using Ka = [H+][X-] / [HX]
    1.3*10^-4 = z^2/0.03
    z=1.97*10^-3 = [H+]

    Ionization % for 0.03M =1.97*10^-3/0.03 *100%

    I'm not too sure if this is correct, haven't done this is awhile and quite rusty
    (Do check the calculations too)

    posted by Anonymous

Respond to this Question

First Name

Your Answer

Similar Questions

  1. chem

    A weak acid, HA, has an ionization constant of 9.29 x 10-6. If we prepare a solution that is 0.727 M in HA what percent of the acid will be ionized?
  2. chem

    A weak acid, HA, has an ionization constant of 4.34 x 10-8. If we prepare a solution that is 0.273 M in HA what percent of the acid will be ionized
  3. Chemistry 104

    A 0.30M solution of a weak monoprotic acid is 0.41% ionized. what is the acid-ionization constant, Ka for this acid? Use. HA + H2O <==> H3O + A to figure out X for H3O and A
  4. 1 more chem check.

    Alright, here is my question: 22. References list the Ka value of hydrosulphuric acid, H 2S(aq) , as 1.1 x 10^–7 at 25°C. Assume a solution is prepared by dissolving 1.00 g of H2S(g) to make 1.00 L of acidic solution. What
  5. chemistry

    A student prepared a .10M solution of acidic acid. Acidic acid has a Ka of 1.75 x 10-3. What are the hydronium ion concentration and the PH of the solution? I think the PH is 1.76 because I hit -log(1.75 x 10-3) on my calculator
  6. AP Chemistry

    A given weak acid HZ has a Ka=1.7×10−6. What is the H3O+ concentration of a solution of HZ that has a concentration of 0.78 mol/L? What is the pH of this solution of HZ? What is the percent ionization of HZ in this
  7. Chemistry

    What will happen if a small amount of hydrochloric acid is added to a 0.1 M solution of HF? A) The percent ionization of HF will increase. B) The percent ionization of HF will decrease. C) The percent ionization of HF will remain
  8. chemistry

    Caclulate the Ka of nitrous acid if a 0.200 mol/L solution at equilibrium at SATP has a percent ionization of 5.8% ka=(H+)(NO2-)/(HNO2-) If 1.59% ionized then after ionization H+ = 0.2 x 0.058 =? NO2- = 0.2 X 0.058=? HNO2=0.2 x
  9. Chem II

    A 0.10 M HF solution is 8.4% ionized. Calculate the H^+ ion concentration. The "8.4% ionized" is throwing me. This is my line of thinking. For every mole HF disolved yeilds one mole of H^+. Since there is 0.10 M HF and the
  10. chemistry

    What is the percent ionization of a 1.38 mol/L weak acid if its Ka = 2.7 x 10-6? Answer to two (2) decimal places. I know what steps to use but have difficulty applying them to the quesiton Can someone please complete the question

More Similar Questions