Review the lab data found in data table 3 this is

1. Review the lab data found in Data Table 3. This is from a titration of a vinegar
sample using a pH meter.
2. Determine the volume of 0.1M NaOH consumed during the titration. Record the
answer.
3. Calculate the Molarity of the Acetic Acid in the vinegar samples. Record the
answer.
4. Calculate the pK
a
of acetic acid from the midpoint data using the Henderson-
Hasselbach equations in the Background section.
5. Find the average calculated molarity, percent by mass concentration, and pK
a
for
acetic acid based on the provided data.
Data Table 3
: Titration of Vinegar by Sodium Hydroxide
Vinegar Sample 1 Vinegar Sample 2 Vinegar Sample 3
Initial pH Reading pH = 3.211 pH = 3.102 pH = 3.105
Initial Buret Reading 2.89 mL 3.00 mL 1.61 mL
Midpoint pH Reading pH = 4.895 pH = 4.687
Midpoint Buret Reading 12.92 mL 9.50 mL
Final pH Reading pH = 8.238 pH = 8.531 pH = 8.934
Final Buret Reading 20.12 mL 20.31 mL 19.00 mL
Volume of NaOH Consumed
Calculated Molarity of Acetic
Acid in the Vinegar Sample
Volume NaOH Consumed at
Midpoint Reading
Moles of NaOH Consumed at
Midpoint Reading [A–]
Moles of Acetic Acid Remaining
at Midpoint [HA]
Calculated p K
a
Average calculated molarity of acetic acid ___________________________
Average acetic acid concentration expressed in percent by mass ___________
Average value of p K
a
of acetic acid based on provided experimental data ____________
Percent error for p K
a
of acetic acid ___________
7
©2014, Carolina Biological Supply
Company

Determination of Acetic Acid Concentration in Vinegar
Using Titration
8
©2014, Carolina Biological Supply
Company