Advanced Chem.  Amino Acids & pH                                      Name:

 

1. A solution has a hydroxide-ion concentration of 1.5 x 10-5M.  (a) What is the concentration of the hydronium ions in

    this solution?  (b) What is the pH of this solution?  (c) Is the solution acidic, basic, or neutral?

 

 

 

2. Calculate the [H+] for a solution with a pOH of 4.75

 

 

3. Calculate the pH of a 0.125 M HNO3 solution.

 

 

4. Calculate the percentage of benzoic acid ionized in a 0.020 M benzoic acid solution.

      Ka is 6.6 x 10-5 for benzoic acid.

 

 

 

5. Calculate the pH for a 0.015 M acetic acid solution. The Ka is 1.8 x 10-5 for acetic acid.

 

 

 

6. Citric acid, a tricarboxylic acid important in intermediary metabolism, can be symbolized as H3A.  Its dissociation reactions are

            H3A                   H+   +  H2A-               pKa1 = 3.13

            H2A-                   H+   +  HA-2               pKa2 = 4.76

            HA-2                   H+   +  A-3                  pKa3 = 6.40

 

If the total concentration of the acid and its anion forms is 0.02 M, what are the individual concentrations of H3A, H2A-,

   HA-2and A-3 at pH 5.2?

 

 

 

 

7. The Ka for formic acid is 1.78 x 10-4. 

  1. What is the pH of a 0.1 M solution of formic acid

 

 

  1. 150 mL of 0.1 M NaOH is added to 200 mL of 0.1 M formic acid, and water is added to give a final volume of 1L.

          What is the pH of the final solution?

 

 

 

 

8. What concentrations of acetic acid and sodium acetate are required to prepare a buffer solution with a pH of 4.60? 

      Ka is 1.8 x 10-5 for aceti