The manufacturer of vinegar used in this experiment claims that the vinegar contains 5% acetic acid by weight. Use your results, the molecular weight of HC2H3O2 and a density of 1.0 g/mL to determine if this claim is true or false.
Results Molarity of NaOH: 0.17M Trial Titration Initial buret reading: 0.0 ml Final buret reading: 25.5 ml Volume of NaOH: 25.5 ml 2. Exact Titrations Initial buret reading Final buret reading Volume of NaOH Concentration 23.3 23.3 79 23.0 23.0 78 22.7 22.7 3. Average concentration of HC2H3O2 0.79M 0.78M + 0.77M '3 = 0.78M 4. Does the vinegar used in the experiment contain 5% acetic acid by weight as the manufacturer claims? Volume of vinegar taken: 5.0 ml Concentration of acetic acid in vinegar: 0.78M Number of moles of acetic acid Molecular weight of acetic acid: 60.05g/mol Amount of acetic acid Density of vinegar:
Pay close attention to the significant figures in the calculations involving the vinegar analysis!
Question 7
What is the concentration of acetic acid determined in Run 1?
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Question 8
What is the concentration of acetic acid determined in Run 2?
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Question 9
What is the concentration of acetic acid determined in Run 3?
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Question 10
What is the average concentration of acetic acid for the three runs ?
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Question 11
What is the average deviation of the concentration of acetic acid?
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Question 12
What is the percent deviation of the concentration of acetic acid?
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Question 13
Would changing the volume of distilled water added to the vinegar samples before titrating have changed the concentrations of acid that you determined?
A. Yes
B. No
C. It is not possible to tell from the data given
Enter Your Answer: A B C
Question 14
If the actual concentration of acetic acid was 0.419, what is the percent deviation of the average result from the actual concentration?
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Question 15
The pH of a sample of the undiluted unknown vinegar solution is measured to be 2.53. What is the pKa of the acetic acid?
