Please answer all 4 parts , and please make sure to actually walk through the lo

Question

Please answer all 4 parts, and please make sure to actually walk through the logic step-by-step as the question asks. The last guy just skipped from Step 1 > Last Step. :(

Students performing vinegar analyses made several mistakes in their experiments. Explain in detail how each error below will affect the final result (% weight of acetic acid in vinegar) of each student's experiment. Show all steps of logic followed in analyzing the effects of the mistake (remember that the experiment had two parts):

1.Student A used a wet beaker to transfer the NaOH solution to be standardized from its original container to the buret.

2.Student B did not fill the tip of the buret with titrant before starting the NaOH standardization, so the tip contained air when the titration was started, but was filled after the first standardization.

3.Student C over-titrated the php solution, but ignored it and continued on with calculations.

4.Student D was in a hurry to leave the lab. He finished the titration of vinegar without waiting for the pink color to persist for 15 seconds. He recorded the volume of NaOH used, just to notice that the pink color disappeared. He ignored this observation and proceeded with calculations.

Explanation / Answer

1. If you use a wet beaker of NaOH means you are not using the exact molarity of solution for reaction. Since NaOH is to be standardized it will result in a lower concentration of NaOH since you have already diluted it before the reaction.

2. If the tip of the buret is filled with air this means that the reading shown by the buret at the end of reaction will be slightly higher than the actual volume used in reaction because error is added due to unfillled buret tip. So this will lead to a lower value of calculated NaOH concentration than real.

3. If student over titrated the solution this menas that he used more than necessary volume of the NaOH for the reaction. So if now student uses this higher value in calculations this means it will result in lower value of calculated concentration of NaOH.

4. Appearance of of persisting pink color is theindication of completion of reaction. It always happens that due to improper mixing solution shows temporary pink color before reaching the end point of reaction but that color do no persists for more than 15 seconds. So if this point is ignored and reading is taken before reaching end point of reaction then you have recorded small than real value of NaOH volume. This menas after calculations you will get higher value of concentration of NaOH than real value.

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