Procedure

Simulator-Guided Step-by-Step Procedure of the Experiment

Experimental Setup

• Burette: Filled with the standardized 0.1M NaOH solution, clamped securely in a stand for controlled titration.
• Beaker: Contains 50 mL of the weak acid solution for titration.
• Magnetic Stirrer: Used to stir the acid solution continuously to ensure uniform mixing during titration.
• pH Meter: A digital pH meter connected to a glass electrode for real-time pH measurements.
• Glass Electrode: Properly calibrated and submerged in the acid solution to accurately measure pH changes.

Procedure

1. Prepare a 0.1M solution of the weak acid.
2. Standardize a 0.1M NaOH solution.
3. Fill a burette with NaOH.
4. Place the acid solution in a beaker and insert a pH electrode.
5. Add NaOH in small increments while stirring and record the pH.
6. Continue adding NaOH until the pH remains stable.
7. Plot pH vs. volume of NaOH added.
8. Identify the equivalence point and determine the pKa values using the Henderson-Hasselbalch equation.

Results

The titration curve shows a gradual increase in pH followed by a steep rise near the equivalence point.

The pKa value is estimated by locating the midpoint of the buffering region.

Conclusion

This experiment successfully determines the pKa value of the given weak acid. The obtained titration curve aligns with theoretical expectations, validating the experimental approach.