In this experiment NaOH is standardized to find out the percent by mass of the acetic acid in a sample of vinegar.


A student had not allowed the NaOH pellets to dissolve completely before standardizing it with KHP, but when the student refilled the buret with NaOH to titrate the acetic acid, the remaining pellets dissolved. Will the molarity of acetic acid in the vinegar solution be too high or low?

Will the concentration of the acetic acid in the vinegar solution will be larger because it takes less NaOH than it should to titrate the acetic acid, meaning the volume of NaOH was small that was required to titrate the acetic acid making the concentration of acetic acid to be larger?

Yes, the concentration of the acetic acid in the vinegar solution will be larger than it should be. This is because the student did not allow the NaOH pellets to dissolve completely before standardizing it with KHP. This means that the volume of NaOH used to titrate the acetic acid was smaller than it should have been, resulting in a higher concentration of acetic acid in the vinegar solution.

Yes, you are correct. The concentration of acetic acid in the vinegar solution will appear to be larger because the volume of NaOH required to titrate the acetic acid will be smaller than it should be. This is due to the fact that some of the NaOH pellets did not dissolve completely during the standardization process. In other words, the molarity of the NaOH solution used for titration was lower than it should have been.

To understand this better, let's break down the process step by step:

1. The student starts by standardizing NaOH solution with KHP (Potassium Hydrogen Phthalate), which has a known concentration. This allows the student to determine the exact molarity of the NaOH solution.

2. However, in this case, the student did not allow the NaOH pellets to dissolve completely during the standardization process. As a result, the molarity of the NaOH solution used for standardization would be lower than it should have been.

3. When the student refilled the buret with NaOH to titrate the acetic acid in the vinegar, the remaining NaOH pellets dissolved completely. Now, the fresh NaOH solution used for titration is at the correct molarity.

4. When the student performs the titration, they will observe that it takes less NaOH than expected to neutralize the acetic acid in the vinegar solution. This is because the molarity of the NaOH solution is lower due to incomplete dissolution during standardization.

5. The smaller volume of NaOH used for titration makes it seem like the concentration of acetic acid in the vinegar solution is higher than it actually is. This is an error caused by the incomplete dissolution of NaOH pellets during standardization.

So, in conclusion, the concentration of acetic acid in the vinegar solution will appear to be larger due to the incomplete dissolution of NaOH pellets.

No, the concentration of acetic acid in the vinegar solution will not be larger. The fact that the remaining NaOH pellets dissolved when the buret was refilled does not affect the concentration of acetic acid in the vinegar solution.

The molarity of the acetic acid in the vinegar solution will be unaffected by the dissolution of the NaOH pellets. The molarity of the acetic acid is determined by the balanced equation and the volume of NaOH required to titrate it, not by the physical state of the NaOH pellets.

Therefore, the molarity of the acetic acid in the vinegar solution will not be too high or too low due to the dissolution of the NaOH pellets.