Wood the following technique errors result In an incorrectly high or incorrectly

Question

Wood the following technique errors result In an incorrectly high or incorrectly low calculated mass percent of acetic acid d vinegar? Briefly explain. A student properly followed Part I of the Procedure. but there was air In the pipit stem when he titrated the vinegar in Part II, causing some of the drops of NaOH solution to be much smaller than the standard size. After standardizing the NaOH solution, a student rinsed the well plate but did not drain the excess water from the welts. Thus, the wells to which ho added the vinegar wore wet) A student failed to standardize his NaOH solution with KHP. Instead, he calculated the NaOH solution concentration from the mass of NaOH his laboratory Instructor dissolved to prepare the solution. Would the procedure you used in this experiment be survivable for the analysis of acetic acid In cider vinegar? Briefly explain. student measured 20 drops of vinegar and ore drop of phenolphthalein solution into a well of her wolf plate. After she had added 35 drops of NaOH solution to the same well, the well was full, but she had still not reached the titration end point. She then took a dean pipit and transferred some of the titration mixture into a second well. She rinsed the pipit with a few drops of distilled water and transferred the rinse water into the titration mixture in the second well. Then she continued adding NaOH solution to both wells until she reached the end point In both wells. She then recorded the total number of drops of NaOH solution added to both wells and used It to calculate the data for her vinegar titration. Briefly comment on her procedure and the accuracy of her results.

Explanation / Answer

1) if there is an air bubble in the burette then the reading of burette will be higher than actual, so it will appear that large volume of NaOH is being used (which is not) so it will give higher value of concentration of acetic acid than the actual one

2) If the well is wet then it will not affect the concentration of vinegar as the number of moles added in well be the same irresptive of excess water

3) we can not prepare primar standard solution of NaOH as NaOH is hygroscopic in nature and may absorb water during weighing, which causes decrease in actual mass of NaOH used during preparation of solution and hence the actual concentration of NaOH will be less as compared to expected concentration, hence the concentration of vinegar will vary.

It will be incorrectely high as more volume of NaOH will be used for end point.

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