Explain how to prepare a buffered solution of known pH and capacity.

Question

Quizplus · Accepted Answer

The Answer is To prepare a buffered solution of known pH and capacity, you will need to follow these steps:

1. Choose a weak acid and its conjugate base or a weak base and its conjugate acid that have a pKa close to the desired pH of the buffered solution. The pKa is the pH at which the acid and its conjugate base are present in equal amounts, and it determines the buffering capacity of the solution.

2. Calculate the amount of the weak acid and its conjugate base or weak base and its conjugate acid needed to achieve the desired buffer capacity. This can be done using the Henderson-Hasselbalch equation, which relates the pH of the buffered solution to the pKa and the concentrations of the acid and its conjugate base or base and its conjugate acid.

3. Measure out the calculated amounts of the weak acid and its conjugate base or weak base and its conjugate acid using a balance or volumetric glassware.

4. Dissolve the weak acid and its conjugate base or weak base and its conjugate acid in a small amount of water to make a concentrated stock solution.

5. Adjust the pH of the stock solution to the desired value using a pH meter and small amounts of a strong acid or base as needed.

6. Once the pH is at the desired value, dilute the stock solution to the final volume with water while maintaining the pH.

By following these steps, you can prepare a buffered solution of known pH and capacity for use in various laboratory experiments and applications.

Explain How to Prepare a Buffered Solution of Known PH