Chemistry Experiment: The Consequences Of Dicture Benzoic Acid

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The list of errors start from the beginning of the experiment. Although the numbers seem to be close to the actual values, there is still room for error with the numbers. What the class noticed first is that we could have been working with very impure benzoic acid. The benzoic acid we were given was made by the 102 chemistry students, meaning that it wasn’t properly made. Students have said that they were rushed and weren’t able to take their time to filter the solid out of the solution. We had to do this for our 102 lab, and I know that our class was being rushed, and it didn’t help that this was the first time working with a funnel filtration. Working with a possible impure benzoic acid is an important thing to note for this experiment. With the uncertainty of whether or not the benzoic acid was impure, the benzoic acid we could have been working with could have not been acid to begin with. A big error that ultimately had an effect on everything we measured was that the pH meter wasn’t fully calibrated since not all the calibrating …show more content…
Water at 25° Celsius always has an auto-ionization constant of 1.0 × 10-14 and HCl is a strong acid which means it has a high Ka of 1 or higher. When HCl is the primary source of H3O+ ions, the pH will always be below 7 because of its high dissociation constant creating an abundance of H3O+ ions. When the HCl solution becomes so diluted that water is the major source of H3O+ ions, the pH will still never go above 7 because the Kw of water will ensure that the H3O+ is 1.0 × 10-7 giving you a pH of 7 exactly, never higher. In order for the solution to have a pH of 8 some sort of base must be added to the solution.

You could determine Ka for benzoic acid by measuring the pH of a 0.010 M solution of benzoic acid. Why is the graphical method you used in this experiment a better way of determining

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