chemistry

what are the hydronium-ion and the hydroxide ion concentration of a solution at 25 C that is 0.0050 M strontium hydroxide, Sr(OH)2?

a solution of hydrochloric acid is 0.20 M HCl. What is the hydronium-ion at 25 C? What is the hydroxide ion concentration at 25 C?

  1. 👍
  2. 👎
  3. 👁
  1. a shampoo solutino at 25 C has a hydroxide ion concentration of 1.5 X a0^-9 M. Is the solutino acidic, neutral, or base

    1. 👍
    2. 👎
  2. Henry, what don't you get about this. It's all about (H^+)(OH^-) = Kw = 1E-14 and pH = -log(H^+).
    Sr(OH)2 is 0.005M so OH^- must be twice that. Go from there.

    1. 👍
    2. 👎
  3. can you tell me whats the difference between hydronium and hydroxide ions are??
    in my book the examples only says H+ ions

    1. 👍
    2. 👎
  4. do you mind solving one of them for me? im kinda confused

    1. 👍
    2. 👎
  5. Henry. Hydronium is the positive ion, shortened to H+ in your book. Hydroxide is the OH- ions.

    because [H+][OH-] in water solutions is Kw (above), if you know one, you can solve the other. { [] means concentration in molarity)

    Here, it is given that Sr(OH)2 concentration is .005M, so OH- concentration must be .010M

    [H+][OH-]=1E-14
    [H+]=1E-14/.010= you do it.

    Now, if [H+] is greater than 1E-7, it is acidic

    remember pH= -log [H+]

    It bothers me you are confused on these. Do you need a regular tutor? If so, get on quickly, do not tarry.

    1. 👍
    2. 👎
    👤
    bobpursley
  6. just to see if im on the right track is the answer for the first equation
    [H+]=Kw/[HCl]=(1.0*10^-14)/0.020=5.0*10^-13
    ??

    1. 👍
    2. 👎
  7. ^^ second equation*

    1. 👍
    2. 👎
  8. H^+ and H3O^+ (hydrogen ions and hydronium ions) are used in many texts as the same thing. Although they are slightly different [(H3O^+) is just a hydrated H^+], most people who use them use them as being the same. At least for problems they can be considered the same.
    Hydroxide ions, on the other hand, are OH^-. When H2O ionizes it does so to produce H2O ==> H^+ + OH^- (a hydrogen ion and a hydroxide ion) and the ion product of (H^+)(OH^-) = a constant which at about 20 C is 1E-14. Therefore, if you know one of them you can calculate the other one. [Note: if we want to be more precise about this the ionization equation is this,
    H2O + H2O (which I will write to help you see it as H2O + HOH ==> H3O^+ + OH^- and (H3O^+)(OH^-) = Kw = 1E-14.
    Now for the Sr(OH)2 problem. Sr(OH)2 is a strong base; therefore, it ionizes 100%. Sr(OH)2 ==> Sr^2+ + 2OH^-
    So if Sr(OH)2 is 0.005, then Sr^2+ = 0.005 and OH^- is 2*0.005 = 0.01.
    So (H^+)(OH^-) = 1E-14
    (H^+)= 1E-14/(OH^-) = 1E-14/(0.01) = 1E-12. Since pH = -log(H^+), then pH = -log(1E-12) = -(-12) = +12.

    There are other ways of doing this which I use most of the time because I thinks its faster. Since pH = -log(H^+), it follows that pOH = -log(OH^-) {and for future reference it also follows that pKa = -log Ka).
    So if (H^+)(OH^+) = Kw then
    pH + pOH = pKw = 14. So I do this in the problem.
    OH^- = 0.005*2 = 0.01.
    pOH = -log(0.01) = -(-2) = 2
    pH + pOH = 14 so
    pH + 2 = 14 and pH = 12
    On the pH scale, pH = 7 is neutral
    pH>7 = basic
    pH<7 = acidic.

    1. 👍
    2. 👎
  9. For the HCl problem, HCl is a strong acid. It has no ionization constant.
    HCl ==>H^+ + Cl^-
    If HCl is 0.20 M then H^+ = 0.20 M
    OH^- = (1E-14/0.2) = ?? but I don't think its 5E-13.(I think you used 0.02 and not 0.20.)

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry II - Concentrations

    At 30.°C, the concentration of hydronium (H3O^+) ions in an aqueous solution is 1.1 ✕ 10^−9 M. (Note: At 30.°C, the ion-product constant for water is 1.46 ✕ 10^−14.) (a) What is the concentration of hydroxide (OH^−)

  2. chemistry

    Calculate the hydroxide ion concentration of a solution with pH = 8.25.

  3. Chemistry

    In aqueous solution, hypobromite ion, BrO-, reacts to produce bromate ion, BrO3 -, and bromide ion, Br-, according to the following chemical equation. 3BrO-(ag) → BrO3 -(ag)+2Br-(ag) A plot of 1/[BrO-] vs. time is linear and the

  4. Chemistry 12

    In s 0.30 mol/L HNO3(aq) solution. a) what is the concentration of nitric acid molecules. b)what is the hydroxide ion concentration?

  1. chemistry

    calculate the hydronium ion concentration in an aqueous solution that contains 2.50x10^-6M in hydroxide solution

  2. Chemisty

    Which solution contains more acid, 50ml of a 0.20 N HCL solution or 50 ml of a 0.20 N acetic acid solution? Which has a higher hydronium ion concentration? Which has a lower pH?

  3. Chemistry 102

    The Ksp for cerium iodate, Ce(IO3)3 is 3.2 e-10. What is the molar solubility of Ce ion in pure water? = .0019 M B) A 0.031 M sodium iodate is added as a common ion. What is the concentration of Ce ion with the common ion present?

  4. Chem

    what is the hydronium-ion concentration at equilibrium in a 0.71 M solution of aniline (Kb=4.2x10^-10) at 25 Celsius

  1. Chemistry

    The pH of a solution is 1. Which of the following statements are also true for the solution? (Select all that apply.) It will change the color of red litmus to blue. The concentration of hydronium ion is equal to the concentration

  2. Chemistry

    Show that the hydroxide-ion concentration in an aqueous solution is 1x10-4 M when the hydronium-ion concentration is 1x10-10 M.

  3. chemistry

    Calculate the hydronium ion consentration and the hydroxide concentration in blood in which the PH is 7.3. Hydronium = [H3O+] = 10-pH or [H3O+] = antilog (- pH) and I got 1.00 x 10^7.3 for both concentrations is this correct?

  4. chemistry

    Suppose that you wanted to be sure that a metal ion, any metal ion, would dissolve in water. What salt of the metal ion compound would you choose? 1. the hydroxide (OH−) salt of the metal ion 2. the carbonate (CO2− 3 ) salt of

You can view more similar questions or ask a new question.