1) What is the hydronium concentration of 0.03M solution of C₃H₇COOH, butanoic acid?
      What is the percent ionization?  The K_a of butanoic acid is 1.52x10^-5.

       C₃H₇COOH    +   H₂O  <--->  C₃H₇COO^-    +   H₃O⁺

          6.75 x 10^-4 M =  x  =   [C₃H₇COO^-]  =  [H₃O⁺ ]    

        % ionization =     2.25%
                              

2) What is the K_a of  0.15M citric acid, C₄H₆O(COOH)₃ when [C₄H₆O(COOH)₂COO^-]
      is 0.011M?

        C₄H₆O(COOH)₃  +   H₂O  <--->  C₄H₆O(COOH)₂COO^-  +   H₃O⁺

         K_a =  7.44 x 10^-4

3) What is the K_b of  2.8M phosphate, PO₄^3- when [OH^-] is 0.198M?

     PO₄^3- +  H₂O  <--->  PO₄H^2-  +  OH^-

      K_b =  1.4 x 10^-2

4) What is the hydroxyl concentration of a 0.2M solution of ammonia, NH₃? 
     What is the percent ionization?  The K_b of ammonia is 1.74 x 10^-5. 

       NH₃  +   H₂O  <--->  OH^-    + NH₄⁺

         1.87 x 10^-3 M =  x  =   [OH^-]  =  [NH₄⁺ ]    

        % ionization =    .93%
               

COMMON ION PROBLEMS

5)  What is the hydronium ion concentration, [H₃O⁺], in a solution of 0.521M HKCO₃ and 
      0.024 M K₂CO₃?  Ka of  HKCO₃ is 4.37 x 10^-7.  

       HKCO₃  +   H₂O <-->  1H₃O⁺  +  KCO₃^-  (+ KCO₃^-  + KOH)         

        9.49 x 10^-6 = X =  [H₃O⁺]

6)  What is the hydronium ion concentration, [H₃O⁺], in a solution of  1.13M HBO₃^-2 and 
      0.02 M Na₃BO₃?  Ka of  HBO₃^-2 is 1.58 x 10^-14. 

      H BO₃^-2 +   H₂O <-->  1H₃O⁺  +  BO₃^-3   (+ BO₃^-3  + Na₃OH₃)  

      8.93 x 10^-13 = X =  [H₃O⁺]

TITRATION PROBLEMS

7) How many mL of  0.15 M KOH are needed to neutralize 25.00 mL of  .20 M HCl?

    HCl + KOH <--> KCl + HOH

    33.33 mL KOH required to neutralize HCl

8) If 28.25 mL of 0.50 M NaOH are needed to neutralize 50.00 mL of  HNO₃, what
    is the concentration of HNO₃? 

    HNO₃ + NaOH <-->  NaNO₃ + HOH

    0.283 M HNO₃ is the concentration of the acid