Practice: Determine the pH of a solution made by dissolving 6.1 g of sodium cyanide, NaCN, in enough water to make a 500.0 mL of solution. (MW of NaCN = 49.01 g/mol). The K_{a} value of HCN is 4.9 × 10^{−}^{10}.

**Weak Bases** partially ionize or dissociate when placed in a solution

Concept #1: **Weak Bases** require an **ICE Chart** to determine their pH.

Example #1: Calculate the hydroxide ion concentration of a 0.55 M KF solution at 25ºC. The acid dissociation constant of HF is 3.5 x 10^{-4}.

Example #2: What is the pH of a 0.12 M ethylamine, C_{2}H_{5}NH_{2}, solution? The K_{b} value of ethylamine is 5.6 x 10^{-4}.

Concept #2: **Weak Bases** are weak electrolytes and so will ionize less than 100%.

Example #3: Calculate the percent ionization when 73.2 g sodium hypoiodite, NaIO, are dissolved with 500 mL of solution. The K_{a} value of hypoiodous acid, HIO, is 2.3 x 10^{-11}.

Practice: Determine the pH of a solution made by dissolving 6.1 g of sodium cyanide, NaCN, in enough water to make a 500.0 mL of solution. (MW of NaCN = 49.01 g/mol). The K_{a} value of HCN is 4.9 × 10^{−}^{10}.

Practice: An unknown weak base has an initial concentration of 0.750 M with a pH of 8.03. Calculate its equilibrium base constant.