1. In the determination of an equilibrium constant of a weak acid, why isn't it necessary to know the concentration of the weak acid?
2. 41.89 mL of NaOH were required to completely titrate 25.00mL of a weak monoprotic acid. After 11.90 mL of NaOH had been added to the solution, the pH of the solution was 6.81. Calculate Ka and pKa for this weak acid.
3. A .45 M solution of NH4Cl has an acidic pH.
a) Write a net ionic equation accounting for this.
b) For the reaction in part a, write the equilibrium constant expression and calculate the equilibrium constant from a consideration of Kb and Kw.
c) Calculate the [H3O+] for a .45 M NH4Cl solution.
d) Calculate the degree (percent) of hydrolysis of .45 M NH4Cl.
e) For each of the salts listed below, indicate whether its water solution would be acidic, basic, or neutral.
NaBr, Na2CO3, KHSO4, KCN, NH4CH3COO, BaF2