ACA

Last modified: Wed 12/31/1969 06:00:00 pm ACA

Oklahoma State University

It is OK to use your textbook or lecture notes from class, but if you can answers the questions without it that is OK too.

Do not press the RETURN or ENTER key while you are answering these questions. Your browser will interpret either the same as clicking on the Submit key.

Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.

First Name:

Last Name:

Laboratory Section:

1. H₂SO₃(aq) is a diprotic acid. Given a 0.100 M H₂SO₃ solution, calculate the of [H⁺] and [HSO₃^-] produced in the first dissociation. NOTE: K_a1(H₂SO₃) = 1.7 x 10^-2. Watch out! you will HAVE to use the quadratic equation to solve for 'x' in this problem.

a) [H⁺] = M

b) [HSO₃^-] = M

2. Calculate the of [H⁺] and [SO₃^2-] in the second dissociation. NOTE: K_a2(H₂SO₃) = 6.4 x 10^-8.

a) [H⁺] = M

b) [SO₃^2-] = M

3. Which dissociation for a diprotic acid contributes the most to the [H⁺] in the solution, the first dissociation or the second?

4. Given 0.100 M solutions of each of the following diprotic acids order them from lowest (most acidic) to highest pH (least acidic). (NOTE: Here is a table of equilibrium constants to help answer this question.)

H₂SO₃ : H₂S : H₂SO₄: H₂CO₃ : H₂C₂O₄

< < < <

5. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

6. If there is one question you would like to have answered in lecture, what would that question be?