# Calculating the expected pH of the buffer solution: Given that the pKa for Acetic Acid is 4.

Calculating the expected pH of the buffer solution:

Given that the pKa for Acetic Acid is 4.77, calculate the expected pH of the buffer solutions using the Henderson-Hasselbalch equation and the concentrations of Acetic Acid and Acetate added to the 250 ml Erlenmeyer flask:

pH = pKa + log { [base] / [acid] }

= ?

[CH3COOH]=[CH3COO-]

Ph= pKa + log ( base/ acid)

Ph = pKa + log ([CH3COO-]/[CH3COOH]

Ph = 4.77+ log 1

pH = 4.77 for both acetate and acetic acid

Hints:

moles of base = mass of NaC2H3O2 / GMW of NaC2H3O2

(GMW available from Chemicals dialog box under Info)

moles of acid = volume of C2H4O2 in litres x molarity of C2H4O2

Preparation the buffer solution:

initial pH of buffer solution: ____

Titration of a weak acid with a strong base:

initial pH of weak acid: ____

final pH of weak acid: ____

Titration Curve for Weak Acid with a Strong Base

(Paste curve here*.)

Titration of buffer with a strong base:

pH of buffer solution: ____

Titration Curve for Buffer with a Strong Base

(Paste curve here*.)

Titration of the buffer with a strong acid:

pH of buffer solution: ____