A 25.00 mL sample of 0.100 M propanoic acid (CH₃CH₂COOH) is titrated at 25 °C with…
CHEMISTRY · Multi-part · AP · Chemistry · Acids and Bases · Acids and Bases
Problem
A 25.00 mL sample of 0.100 M propanoic acid (CH₃CH₂COOH) is titrated at 25 °C with 0.100 M NaOH. After exactly 12.50 mL of the NaOH solution has been delivered, the pH of the mixture is measured to be 4.87.
(a) Calculate the number of moles of CH₃CH₂COOH and CH₃CH₂COO⁻ present in the reaction vessel after the addition of the 12.50 mL aliquot of NaOH. Assume volumes are additive.
(b) Using the information from part (a) and the measured pH, determine the experimental pKₐ of propanoic acid at 25 °C.
(c) The accepted pKₐ of propanoic acid at 25 °C is 4.87. Determine the percent difference between the experimental pKₐ and the accepted value, and comment briefly on the accuracy of the experiment.