Final answer:
The pH of a 0.25 M solution of ethanolamine with a Kb value of 3.2x10⁻⁵ is 5.10.
Step-by-step explanation:
The pH of a solution can be calculated using the formula: pH = -log[H⁺], where [H⁺] is the concentration of hydrogen ions. The concentration of hydroxide ions can be determined by using the formula: [OH⁻] = Kb * [base], where Kb is the ionization constant and [base] is the concentration of the base.
In this case, the base is ethanolamine (HOCH₂CH₂NH₂), which has a concentration of 0.25 M. The Kb value for ethanolamine is 3.2x10⁻⁵. Plugging the values into the formula, we get:
[OH⁻] = (3.2x10⁻⁵) * (0.25) = 8x10⁻⁶ M.
Since the solution is neutral, the concentration of [H⁺] is equal to [OH⁻]. Therefore, the pH of the solution is:
pH = -log(8x10⁻⁶) = 5.10.