Answer to Question #126364 in General Chemistry for jake

Question

The equivalence point happens when 36.0 mL of base has been added. If the pH when 18.0 mL of base has been added is 4.25, what is the value of Ka for this weak acid?

Answer 1

At half equivalence point:

pH = pKa

4.25 = -logKa

Ka = 5.62×10^-5 (Answer)

The value of Ka for this weak acid is 5.62×10^-5.