Answer to Question #79160 in General Chemistry for abigail

Question

A certain weak acid, HA, with a Ka value of 5.61×10−6, is titrated with NaOH.More strong base is added until the equivalence point is reached. What is the pH of this solution at the equivalence point if the total volume is 30.0 mL ?

Answer 1

If we assume that the concentrations of acid and base are equal [base] = [acid], then the Henderson-Hasselbalch equation:

pH = pKa + log ([base]/[acid])

[base] = molar concentration of a conjugate base

[acid] = molar concentration of a undissociated weak acid (M)

Ka = 5.61×10^−6 pKa = 5.25

pH = 5.25