Question

Order the steps for how you will determine the pKa of a weak acid using a titration curve?

1) Prepare a solution of the weak acid
2) Add a strong base to the solution
3) Record the pH of the solution as the strong base is added
4) Plot a titration curve of pH versus volume of strong base added
5) Identify the equivalence point on the titration curve
6) Determine the pKa value based on the pH at the half-equivalence point

Answer 1

The pKa of a weak acid can be determined through titration by preparing a solution of the weak acid, titrating with a strong base, recording the pH changes, plotting a titration curve, locating the equivalence and half-equivalence points, and then determining the pKa at the half-equivalence point.

Step-by-step explanation:

When determining the pKa of a weak acid using a titration curve, the steps should be followed in a specific order. Here they are:

1. Prepare a solution of the weak acid.
2. Add a strong base to the solution.
3. Record the pH of the solution as the strong base is added.
4. Plot a titration curve of pH versus volume of strong base added.
5. Identify the equivalence point on the titration curve.
6. Determine the pKa value based on the pH at the half-equivalence point.

A titration curve allows for the visualization of pH changes during the titration process. The point at which the acid and base react completely to each other is known as the equivalence point, which differs in pH level depending on whether the titrated substance is a strong or weak acid/base. Particularly for weak acids, the pKa can be assessed by identifying the half-equivalence point on the titration curve, which corresponds to the pKa of the acid.