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 for me since there are about 10 other questions just like this one on my practice sheet.

Step one is to use an ICE grid.

Step two is to use an ionization equation.

Step three is to use the equilibrium constant expression.

Step four is to solve the equation.

Step five is to use the quadratic.

Step six is to determine percent ionization by dividing ionized over initial concentration

  1. 👍 0
  2. 👎 0
  3. 👁 355
  1. Can someone please complete the question for me since there are about 10 other questions just like this one on my practice sheet.
    First you write the ionization equation. For a weak acid, which I will call HA, it ionizes as follows:
    HA <==> H^+ + A^-

    Next you want to write the Ka expression.
    Ka = (H^+)(A^-)/(HA) = 2.7 x 10^-6


    Step one is to use an ICE grid.
    For spacing reasons, this board doesn't handle multiple spaces at all; therefore, I will need to covert this a little differently. Basically, I do it vertically, like this.
    I
    C
    E
    Initial concn:
    (HA) = 1.38 M
    (H^+) = 0
    (A^-) = 0

    Change in concn:
    (H^+) = +y
    (A^-) = +y
    (HA) = -y

    Equilibrium concn:
    (HA) = 1.38 - y
    (H^+) = 0 + y = y
    (A^-) = 0 + y = y


    Step two is to use an ionization equation.

    Step three is to use the equilibrium constant expression.

    Step four is to solve the equation.
    I will leave the equation for you to solve. You may want to try making the simplifying assumption that 1.38 - y = 1.38. That will avoid solving a quadratic IF it is almost true.

    Step five is to use the quadratic.

    Step six is to determine percent ionization by dividing ionized over initial concentration
    percent ionization = (amount ionized/amount to start)*100.

    The amount ionized is just (H^+) so you can use that for the numerator. The amount unionized will be 1.38. Then multiply by 100 to convert to percent.
    Post your work if you get stuck.

    1. 👍 0
    2. 👎 0
  2. 1.38 x 100 = 1.4%

    Is this correct?

    1. 👍 0
    2. 👎 0
  3. No it isn't. I gave step by step instructions and worked most of it. You didn't follow any of them except to multiply by 100 to change to percent.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. 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

  2. chemistry

    a) Calculate the percent ionization of 0.125M lactic acid (Ka=1.4x10^-4) b) Calculate the percent ionization of 0.125M lactic acid in a solution containing 0.00075 M sodium lactate.

  3. Chem

    What simplifying assumptions do we usually make in working problems involving equilibria of salts of polyprotic acids? Why are they usually valid? Answer by selecting all true statements. Are the answers: a,b,d,and f A)If the two

  4. chemistry

    Weak Acid 1.) The pH of a 0.060M weak monoprotic acid HA is 3.44. Calculate the Ka of the acid. 2.) The pH of 0.100M solution of weak monoprotic acid HA is 2.85. What is the Ka of the acid?

  1. Chemistry

    Calculate the percent ionization of nitrous acid in a solution that is 0.311 M in nitrous acid (HNO2) and 0.189 M in potassium nitrite (KNO2). The acid dissociation constant of nitrous acid is 4.50 Ɨ 10-4.

  2. Chemistry

    Given acidity constant,Ka of benzoic acid is 6.28 X 10^-5. pH of 0.15 molar solution of this acid is ? Here is my method: Benzoic acid is a weak acid,hence it dissociates very little. So: C6H5COOH---> C6H5COO- + H+ [H+] and

  3. chemistry

    Enter a chemical equation for the ionization in water of CH3CH2COOH. Is the acid strong or weak? Select the Lewis structure for the ion formed by the acid when it ionizes. Chemical equation: Note: Include physical states.

  4. chem

    Diethylamine, (C2H5)2NH, is a weak base with Kb = 6.92Ɨ10āˆ’4 at 25 oC. For a 0.133 mol Lāˆ’1 solution of (C2H5)2NH at 25 oC, what is the percent ionization of (C2H5)2NH?

  1. chemistry

    Calculate the ionization constant, Ka, of phenol (HC6H5O), a weak acid, if a 0.25 M solution of it has a pH of 5.24.

  2. Chemistry

    The pH of a 0.010 M aqueous solution of a weak monoprotic acid, HX, is 4.5. What is the value of the acid ionization constant?

  3. chemistry

    propanoic acid ch3ch2cooh is a weak acid which has a value for dissociation content of ka = 6.3 x 10^-6 calculate the pH of an aqueous solution of propanoic acid containing 37 g of propanoic acid per litre. i'm stumbled on this

  4. CHEM HELP

    Nicotinic acid (niacin) is a monoprotic acid with the formula HC6H4NO2. A solution that is 0.012M in nicotinic acid has a pH of 3.39 at 25*C. What is the acid-ionization constant, Ka and pKa for this acid at 25*C? is the

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