Titration Laboratory

We know that that the end point of the titration is reached when, after drop after careful drop of NaOH, the solution in the flask retains its pale pink color while swirling for about 30

H. How would you prepare 10 mL of a 0.25M HCl solution if 1M HCl was available? How much

2. In Part 1, why did you not observe a stream of bubbles coming off the stainless steel screw in the sugar solution?

* By using the dropper and measuring cylinder, an amount of 5ml milk was placed in the test tube

weak bases). After ranking the pH of these solutions, you will then test your predictions in the laboratory.

To start out this study the difference between acids and bases has to be identified. Acids have very low pHs and have a high concentration of hydronium ions, while bases have a high pH and have a high concentration of hydroxide ions. The difference between strong bases and acids, and weak bases and acids is the amount of dissociation. Strong bases and acids dissociate a large amount and let go of their ions in solution, while weak bases and acids may only let go of some of their ions. This is important because if the unknown solutions aren’t strong acids or bases then using their ions to calculate the pH of the solutions will give false results (Diffen 2012).

After the twenty minutes elapsed, the flask was cooled to room temperature and then titrated with the remaining NaOH until the colorless solution remained pink. The final volume was then recorded. While solution #1 was heating the same process was repeated with solution#2 and the second burette

9. How many moles of NaOH would be needed to completely react with all of the excess HCl determined in problem 8?

By using the pH paper to measure the solutions A through E it would point out what substance is an acid and which one was basic. Also, by adding Bromothymol blue and Phenolphthalein afterwards to the solution it would indicate what color it would turn to when mixed into an acid and a base.

Volumetric burette: This instrument was filled with the sodium hydroxide solution that would be gradually added to the vinegar solution. The burette was used instead of a measuring cylinder as it gives a finer volume

To begin, three sets ofabout 0.3000g of KHP are weighed out on an analytical balance. Put the three sets of KHP into three separate, labeled flasks. All three sets of the KHP is then dissolved with approximately 50mL of deionized water. Next, a buret is used to start the actual titration. Buret is initially filled to 0.00mL mark with the NaOH solution, this is recorded as initial volume. Next, add 2-3 drops of phenolphthalein indicator into each of the three flasks containing KHP. A magnetic stir bar is then added to the first flask, and placed above a stir plate. Everything is positioned under the buret. Stirrer is put on medium speed and the titration can start. Slowly release the NaOH into the KHP flask. As the end point is reached, a pink color will be seen in the flask. When the lightest pink possible remains in the solution for more than 30 seconds titration is complete. The final volume is recorded, and the same steps are taken for the other two sets of KHP solution. Finally, blank titration is completed to determine deviation.

b. As I mentioned above that I spilled some of the benzoic acid therefore the initial mass

During a titration the pH of the solution will be monitored using a pH meter from that we get a titration curve. The titration curve is then used to determine the equivalent molecular weight and Ka value of the unknown weak acid, from that we are

Using Graph 1: The Volume of Titrant Added in order to reach the Endpoint and the Corresponding pH Values, observe the vertical line of each titration and see the points in which the horizontal lines intersect it. These points give the

3. A few drops of 6 M acetic acid were added until it became basic.