A solution of boric acid (H3BO3) in water has a pH of 3.45. If the solution also contained NaHBO3, what do you expect to happen to the pH?
Increase
Decrease
Stay the same
Not enough information provided
Increase.
To determine what will happen to the pH of the solution when NaHBO3 is added, we need to understand the properties of boric acid and NaHBO3.
Boric acid is a weak acid and undergoes partial dissociation in water, resulting in the release of H+ ions. This leads to a decrease in the pH of the solution.
NaHBO3, on the other hand, is the sodium salt of boric acid. When it dissolves in water, it dissociates into Na+ and H2BO3- ions. The H2BO3- ions can further react with water to release H+ ions and convert into H3BO3, which is the acidic form of boric acid.
Adding NaHBO3 to the boric acid solution increases the concentration of H2BO3- ions and provides an additional source of H+ ions through the reaction with water. Consequently, this will lead to an increase in the concentration of H+ ions in the solution, resulting in a decrease in pH.
Therefore, the pH of the solution is expected to decrease when NaHBO3 is added. The correct answer is "Decrease."