Hi, I am asked to do this:
12. A buffer solution containing HBO32 –(aq) and BO33 –(aq) ions is used to standardize pH meters in the range pH > 7. Write net ionic equations for the reactions that occur in the buffer solution for the following conditions.
a.
To write the net ionic equations for the reactions that occur in a buffer solution containing HBO32 –(aq) and BO33 –(aq) ions, we need to understand the characteristics of the buffer system.
In a buffer system, there is a weak acid (HBO32 –) and its conjugate base (BO33 –) present in roughly equal amounts. This is important because the weak acid can donate H+ ions if the pH of the solution becomes too high, and its conjugate base can accept H+ ions if the pH becomes too low. This ability to resist changes in pH is what makes a buffer solution important for standardizing pH meters.
Now, let's look at the given condition:
a. pH > 7
Since the pH is greater than 7, it means that the solution is more basic. In this condition, the HBO32 – ions in the buffer act as the weak acid, while the BO33 – ions act as the conjugate base.
The net ionic equation for the reaction would be:
HBO32 –(aq) + H2O(l) ⇌ H3O+(aq) + BO33 –(aq)
The HBO32 – ions react with water to form hydronium (H3O+) ions and BO33 – ions.
Note: The reaction is reversible because the buffer system maintains equilibrium between the weak acid and its conjugate base to maintain a stable pH.
Remember, when writing net ionic equations, only the species that undergo chemical changes are included. Water, H2O, is not included as it is a solvent and does not participate in the reaction itself.
I hope this helps you understand how to write the net ionic equation for a buffer solution under specific conditions. If you have any further questions, feel free to ask!