**WEAK ACIDS** and **WEAK BASES** are weak electrolytes that do not completely ionize in solution, but instead form an equilibrium.

Example #1: What is the original molarity of a solution of weak acid with a K_{a} of 4.7 x 10** ^{-3}** and pH of 4.12 at 25

Example #2: You are seeking to identify an unknown monoprotic acid by determining its K_{a} value. A 6.05 x 10** ^{-2 }**M solution of this unknown monoprotic acid has a pH of 2.122. Determine the K

a) 4.47 x 10^{-4}

b) 9.42 x 10^{-4}

c) 2.85 x 10^{-2}

d) 1.08 x 10^{-3}

e) 3.58 x 10^{-1}

Example #3: A weak acid has a pKa of 5.35. What is the hydronium ion concentration in a 0.10 M solution of this weak acid?

a) 5.4 x 10^{-4} M

b) 6.3 x 10^{-6} M

c) 3.5 x 10^{-5} M

d) 2.3 x 10^{-6} M

e) 4.5 x 10^{-6} M

f) 6.7 x 10^{-4} M

Practice: The pH of an aqueous 0.10 M nitrite ion is 8.17. What is the base dissociation constant of the base?