Predict the effect each of the following situations would have on the reported %

Question

Predict the effect each of the following situations would have on the reported % acetic acid in vinegar. Would the value be higher, lower, or unaffected as compared to the true value? Thoroughly explain your answers.

a) You overshoot the endpoint. In other words, the pink color is too dark.

b) Some of the vinegar solution spills out of the flask during the titration.

c) You did not dry the graduated cylinder in which you placed the standardized NaOH solution.

d) You add ten drops of phenolphthalein indicator instead of two.

Explanation / Answer

Predict the effect each of the following situations would have on the reported % acetic acid in vinegar. Would the value be higher, lower, or unaffected as compared to the true value? Thoroughly explain your answers.

When we over shoot the end point that means NaOH is taken more than it is required for exact. By using this volume and molarity of NaOH we get acetic acid. Moles of acetic acid will be calculated more than it is actually present in vinegar. So percent of acetic acid will be increased. Or higher.

Suppose we took 10 mL acetic acid solution in conical flask. And when such solution is spilled then volume will be less than 10 mL and moles of NaOH also be less than required. We find moles of acetic acid in 10 mL (calculation ) but it was actually in less volume. So here percent of acetic acid will be lower than its true value.

There is dilution of NaOH and when acetic acid is titrated with such diluted NaOH then we get more moles of acetic acid that it is present. So here there is higher percent of the acetic acid than its true value.

d) You add ten drops of phenolphthalein indicator instead of two.

Phenolphthalein is an indicator that will not affect the percent.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.