We rinsed the weigh boat with distilled H2O to make sure that all the assured KIP is transferred into the flask and added distilled H2O into the flask until the meniscus of the water touches the line of the flask. We did not measure the amount of H2O added since water doesn’t involve in the reaction. We then swirled and inverted the flask until all the KIP is dissolved into the H2O. In our second part of our experiment to determine the molarities of Noah, we rinsed a burette with about mm] of water and another ml of Noah to prepare it for the experiment.
We then measured exactly ml of the prepared KIP from the previous part into a moll Erlenmeyer flask and added 2 drops of the indicator, phenolphthalein. Next we filled the burette with the approximately 0. 1 M Noah so that our initial volume will be 0. Mils. We then started our titration by carefully pouring a little amount of the base into the prepared ml of KIP with phenolphthalein until we reached the end point. Since the molarities of the Noah was designed to be more or less the same with the acid, we knew that it would take equal amount of the base to reach the endpoint.
Thus we added the first 20 ml in about mi increment and swirled to mix after each addition then added just 6-7 drops for the next ml. After we started observing a pink color, we started adding just 2 drops at a time and swirl the flask. When we reached a persistent pink color, we recorded that final burette to the tenth place as the end point (equivalent point). After that, we calculated the molarities of the Noah based on the reaction between the acid and the base and the prepared molarities and volume of the acid and the volume reading of the base.
We then repeated the same experiment to make sure that our calculated molarities of the base are within 10% difference. In our third part of the experiment to determine the molarities of vinegar, we assured exactly 2. Ml of vinegar using a graduating cylinder into a clean non- dry Erlenmeyer flask. We then added 2 drops of phenolphthalein. Next, we refilled the burette with the base, Noah and recorded the initial volume as 0. Mi. We then titrated with Noah very carefully in a Mil interval since we don’t know the expected equivalent point.
Once the color begins to persist, we slowed our titration to 2-3 drops at a time so that we wouldn’t overshoot the endpoint. We then recorded the final volume when we observed a permanent pink color at the equivalent point and calculated the molarities of the acid using the formula M acetic acid-Moles Noah/Volume in liters of the acid (2. 5 ml) We then had to repeat the experiment twice to make sure our molarities agree within of the values. In our fourth part of the experiment to determine the equilibrium constant of vinegar, we measured 2. Mils of vinegar into a wet flask.
Unlike the previous part of the experiment, we used a pH meter instead of a phenolphthalein indicator. We added ml of distilled water so that we could have enough liquid to dip the electrode/pH meter and recorded the initial pH of the vinegar before the titration started. Then, we filled out the burette and recorded the initial volume as O. Next, we added 0. Ml of the Noah into the vinegar flask and used a pH meter to record the volume. We added the base in a small increment to observe the shape of the titration curve. We repeated the step until we reached a pH of around 1 1 .
We then plotted pH versus total volume OH- using a scatter graph. We then used the graph to determine the peak of the proton dissociation found at the inflection point of the curve. Results: Our first part of our experiment was just a preparation. We prepared a primary standard KIP solution of a 0. M concentration. Our mass of KIP was 2. Egg and the molar weight of KIP is 204. 22 g/mole. From this value, we can find the moles of KIP. AN=Mass/Mm =2. Egg/204. Egg/mol=0. Molecule. The reaction was KIP+ + H2O (l) – HUH+ + KIP – Our second part of our experiment was determining the molarities of the base.