CU Su20 Determination of Acetic Acid Concentration Q PDF

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LAB WORK...

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Determination of Acetic Acid Concentration in Vinegar Using Titration Student Name: Alison Naeve Date: 10/15/2020

1

Introduction What is being determined in this lab? Please provide a brief (2-3 sentences) answer in your own words. The purpose of the lab was to accurately determine the concentration of acetic acid. Activity 1 uses vinegar with a determined amount of acetic acid while activity 2 uses a different sample of vinegar to be titrated.

Data Activity 1 Data Table 1 Vinegar Sample 1

Vinegar Sample 2

Vinegar Sample 3

5.03

5.01

4.97

1 g=1 mL 5.03 g=5.03 mL

5.01

4.97

Initial NaOH Volume in Syringe

10.0

10.0

9.9

Final NaOH Volume in Syringe

6.0

5.9

5.7

Name of Vinegar Sample

Mass of Vinegar

Volume of Vinegar

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2

Name of Vinegar Sample

Vinegar Sample 1

Vinegar Sample 2

Vinegar Sample 3

Volume NaOH Delivered

10-6= 4.0

4.1

4.3

Moles of NaOH Delivered

0.10

0.10

0.10

Moles of Acetic Acid in Sample

0.10

0.10

0.11

Mass of Acetic Acid in Sample

6.0

6.0

6.6

Calculated Molarity of Acetic Acid in Sample Vinegar

20.0

20.0

22

Calculated Percent Mass of Acetic Acid in Sample Vinegar

54.4%

54.5%

51.8%

Average Calculated Percent Mass of Acetic Acid in Sample Vinegar

53.6%

53.6%

53.6%

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3 CH3CO2H+ NaOH- NaCH3CO2+H2O 0.10 mol NaOH * 1 mol CH3CO2H/ 1 mol NaOH = 0.10 mol CH3CO2H 0.10 mol CH3CO2H * 60.052 g CH3CO2H/ 1 mol CH3CO2H= 6.0 g CH3CO2H (0.10 mol CH3CO2H)/ 0.005 L= 20.0 M (Percent mass) (6.0 g/ (5.03 g + 6.0 g)) * 100= 54.4% (average Percent mass) 54.4+54.5 +51.8)/300= 53.6%

Activity 2

Data Table 2 Vinegar Sample 1

Vinegar Sample 2

Vinegar Sample 3

5.02

5.08

4.97

1 g= 1mL 5.02 g= 5.02 mL

5.08

4.97

Initial NaOH Volume in Syringe

9.8

10

9.9

Final NaOH Volume in Syringe

7.6

7.2

7.1

Volume NaOH Delivered

2.2

2.8

2.8

Name of Vinegar Sample

Mass of Vinegar

Volume of Vinegar

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4 Vinegar Sample 1

Vinegar Sample 2

Vinegar Sample 3

Moles of NaOH Delivered

0.055

0.070

0.070

Moles of Acetic Acid in Sample

0.055

0.070

0.070

Mass of Acetic Acid in Sample

3.3

4.2

4.2

Calculated Molarity of Acetic Acid in Sample Vinegar

11

14

14

Calculated Percent Mass of Acetic Acid in Sample Vinegar

39.7%

45.3%

45.8%

Average Calculated Percent Mass of Acetic Acid in Sample Vinegar

43.5%

43.5%

43.5%

Name of Vinegar Sample

% CH3CO2H+NaOH NaCH3CO2+H2O 0.055 mol NaOH * 1 mol CH3CO2H/ 1 mol NaOH+ 0.055 mol CH3CO2H 0.055 mol CH3CO2H* 60.052g CH3CO2H/ 1 mol CH3CO2H= 3.3 g CH3CO2H (0.055 mol CH3CO2H)/ 0.00502= 11 M (Percent mass)- (3.3g/ (3.3g +5.02g)) * 100= 54.4% (Average percent mass)- (39.4+45.3+45.8)/ 300= 43.5% 1. List at least two possible sources of error from the experiment. Would these errors result in an overestimation or an underestimation of the concentration of acetic acid in the vinegar?

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5 Two possible sources of error were the plunger being pushed too hard whi ch would release too much NaOH into the vinegar at once or the error of the scale which could be in not giving an accurate reading. The first source of error could be a result from overestimating the concentration of acetic acid in vinegar. All of these things would result in off or different answers/results.

Photos

Photo 1 Insert the photo of the 25-mL Erlenmeyer flask after the addition of phenolphthalein from Activity 1, step 6.

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6

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7

Photo 2 Insert the photo of the 25-mL Erlenmeyer flask at the endpoint of the titration from Activity 1, step 13.

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8

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9

Conclusion Write a one paragraph (3-5 sentences) statement that provides the scientific objective of the lab, a brief summary of the procedure, and report the major results. The purpose of the lab was to accuratly determine the concentration of acetic acid which we did in activy 1 as well as finding the average calucated percent mass of Acetic acid in a sample (53.6%). In activty 2 a different sample of vinegar yeiled an average percent mass of 43.5%. The concentration of the acetic acid in the sample used in activity 2 was and should be lower than the first was the samples were the same but flushed in the second ecpierament helpign prove our results.

Be sure to show your calculations (at least one sample calculation for every calculated step) by either typing in the calculation under the data table or adding a picture of calculations done by hand!

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