Determination of Acetic Acid from Commercial Vinegar
Essay by Jeb Reece Grabato • February 17, 2018 • Lab Report • 1,588 Words (7 Pages) • 2,785 Views
Name: Jeb Reece Grabato Date Performed: 03/02/2017
Robert John Vidal Group No.: 3
Experiment No. 3
Determination of Acetic Acid Content in Vinegar
- Background
Titration is a method of chemical analysis used to determine the concentration of a substance of known stoichiometric composition. The volume or mass of titrant (a standard reagent) that is needed to react completely with the analyte (the solution being analysed) is determined. The determined value is then used to calculate the amount of analyte (Skoog et al, 2014).
The objective of this experiment is to use volumetric titrations to determine the % w/v concentration of acetic acid from commercial vinegar. The titrant used is ~0.1 M NaOH, and the indicator used is phenolphthalein.
- Results
Table 1. Measurement of Relative Strengths of Acid and Base
Trials | 1 | 2 | 3 |
Final Reading HCl (mL) | 26.00 | 28.50 | 41.95 |
Initial Reading HCl (mL) | 1.00 | 3.35 | 16.92 |
Back-titrated HCl (mL) | 0.47 | 0.18 | |
Volume HCl used (mL) | 25.47 | 25.33 | 25.03 |
Final Reading NaOH (mL) | 25.15 | 35.30 | 26.78 |
Initial Reading NaOH (mL) | 2.62 | 13.02 | 4.20 |
Volume NaOH used (mL) | 22.53 | 22.28 | 22.58 |
Acid to Base Ratio | 1.13049 | 1.13689 | 1.10850 |
Average acid/base ratio | 1.12529 | ||
Standard Deviation | 0.01489 | ||
RSD (ppt) | 13.23 | ||
Base to Acid Ratio | 0.884570 | 0.879589 | 0.902117 |
Average base/acid ratio | 0.888759 | ||
Standard deviation | 0.0118337 | ||
RSD (ppt) | 13.31 |
Primary standard used: KHP
Formula mass of primary standard = 204.22 g/mol
% Purity of primary standard = 99.98%
Table 2. Standardization of NaOH
Trials | 1 | 2 | 3 |
Wt. of std. KHP (g) | 0.7005 | 0.7001 | 0.7047 |
Corrected wt. KHP (g) | 0.7004 | 0.7000 | 0.7046 |
Final Reading NaOH (mL) | 38.75 | 41.52 | 42.55 |
Initial Reading NaOH (mL) | 4.25 | 7.32 | 7.95 |
Volume NaOH used (mL) | 34.50 | 34.20 | 34.60 |
Final Reading HCl (mL) | 42.55 | 42.61 | |
Initial Reading HCl (mL) | 42.50 | 42.55 | |
Volume HCl used (mL) | 0.05 | 0.06 | |
Corrected Vol. of NaOH (mL) | 34.46 | 34.20 | 34.55 |
Molarity of NaOH | 0.09952 | 0.1002 | 0.09986 |
Ave. Molarity of NaOH | 0.09986 | ||
Standard Deviation | 3.400 x 10-4 | ||
RSD (ppt) | 3.405 | ||
Molarity of HCl | 0.08844 | 0.08904 | 0.08874 |
Ave. Molarity of HCl | 0.08874 | ||
RSD (ppt) | 3.3807 |
Table 3. Determining the Acetic Acid Content of Vinegar
Trials | 1 | 2 | 3 |
Vol. of vinegar used (mL) | 25.00 | 25.00 | 25.00 |
Vol. of aliquot used (mL) | 50.00 | 50.00 | 50.00 |
Final Reading NaOH (mL) | 39.50 | 36.10 | 38.50 |
Initial Reading NaOH (mL) | 2.40 | 0.80 | 3.20 |
Volume NaOH used (mL) | 37.10 | 35.30 | 35.30 |
Final Reading HCl (mL) | 45.50 | 45.60 | |
Initial Reading HCl (mL) | 42.61 | 45.50 | |
Volume HCl used (mL) | 2.89 | 0.10 | |
Corrected vol. NaOH (mL) | 34.53 | 35.30 | 35.21 |
% w/v acetic acid | 4.142 % | 4.234 % | 4.223 % |
Ave. % w/v acetic acid | 4.199 % | ||
Standard Deviation | 0.05046 | ||
RSD (ppt) | 12.02 |
...
...
(2018, 02). Determination of Acetic Acid from Commercial Vinegar. OtherPapers.com. Retrieved 02, 2018, from https://www.otherpapers.com/essay/Determination-of-Acetic-Acid-from-Commercial-Vinegar/63409.html
"Determination of Acetic Acid from Commercial Vinegar" OtherPapers.com. 02 2018. 2018. 02 2018 <https://www.otherpapers.com/essay/Determination-of-Acetic-Acid-from-Commercial-Vinegar/63409.html>.
"Determination of Acetic Acid from Commercial Vinegar." OtherPapers.com. OtherPapers.com, 02 2018. Web. 02 2018. <https://www.otherpapers.com/essay/Determination-of-Acetic-Acid-from-Commercial-Vinegar/63409.html>.
"Determination of Acetic Acid from Commercial Vinegar." OtherPapers.com. 02, 2018. Accessed 02, 2018. https://www.otherpapers.com/essay/Determination-of-Acetic-Acid-from-Commercial-Vinegar/63409.html.