Titratie van een zwak zuur met een zwakke base

The titration of a weak acid like acetic acid with a weak base like aqueous ammonia produces a neutral ammonium acetate salt and water.

The titration curve of the weak acid versus weak base is plotted by measuring the pH during the various points of the titration.

In the titration of 100 mL of 0.1 M acetic acid solution with 100 ml of 0.1 M aqueous ammonia, the initial pH is 2.87.

If the weak acid and base possess identical K_a and K_b values, the pH at the equivalence point is 7, suggesting a neutral solution. If K_a is greater than K_b, the pH is less than 7 at the equivalence point. Alternatively, if K_a is less than K_b, the pH is greater than 7.

The pH change during the entire titration curve is gradual, with no sharp end point observed. However, a mix of neutral red and methylene blue indicators may be used to approximate the endpoint.