[UNLOCKED]: Chemistry lab

[UNLOCKED]: Chemistry lab

Question 1

1. If the manufacturer of the vinegar used in the experiment stated that the vinegar contained 5.0% acetic acid, what would the percent error between your result and the manufacturer’s statement be? Show your work.

Question 2

2. What challenges would you encounter with the titration if you had used apple cider vinegar or balsamic vinegar as the analyte instead of distilled white vinegar?

Question 3

3. How would your experimentally determined vinegar concentration have differed if the tip of the titrator was not filled with NaOH before the initial volume reading was recorded? Explain your answer.

Question 4

4. How would your experimentally determined vinegar concentration have differed if you had over-titrated (added drops of NaOH to the analyte beyond the stoichiometric equivalence point)?

Question 5

5. If a 7.0 mL sample of vinegar was titrated to the stoichiometric equivalence point with 7.5 mL of 1.5M NaOH, what is the mass percent of CH3COOH in the vinegar sample? Show your work.

Question 6

6. Why is it important to do multiple trials of a titration, instead of only one trial?

Question 7

7. A student did not read the directions to the experiment properly and mixed up where to place the NaOH solution and the vinegar. He put the vinegar in the titrator and the measured amount of NaOH in the beaker. He then added a drop of the phenolphthalein to the solution in the beaker. Does the student need to empty out all of the solutions and start over again or can he go ahead and run the titration? If he runs the titration using the solutions as given above, what should he expect to see happen for results?

Question 1

Data Table 1: NaOH Titration Volume

  Initial NaOH Volume (mL) Final NaOH Volume (mL) Total volume of NaOH used (mL)

Trial 1    

Trial 2    

Trial 3    

     Average Volume of NaOH Used (mL) :

Question 2

Data Table 2: Concentration of CH3COOH in Vinegar

Average volume of NaOH used (mL) Concentration of CH3COOH in vinegar (mol/L) % CH3COOH in vinegar