Acid-Base Titration Lab Report

1. To titrate a hydrochloric acid solution of “unknown” concentration with standardized 0.5M sodium hydroxide.

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

pH was recorded every time 1.00 mL of NaOH was added to beaker. When the amount of NaOH added to the beaker was about 5.00 mL away from the expected end point, NaOH was added very slowly. Approximately 0.20 mL of NaOH was added until the pH made a jump. The pH was recorded until it reached ~12. This was repeated two more times. The pKa of each trial are determined using the graphs made on excel.

* By using the dropper and measuring cylinder, 7 ml sodium carbonate solution was added to the test tube

Enter the precise mass in GRAMS of the potassium iodate used to prepare your primary standard solution.

In the event of a chemical splash to the eyes, flood the eyes for at least 15-30 minutes with water. Flush from the eye outward. If you were not wearing proper eye wear, a chemical could splash into your eye and would make it necessary to use this.

The manufacturer results shows that Alka-Seltzer has 1.9 grams per tablet. In the experiment the results are too small compared to the number that is given by the label. In the first run only .0588 grams reacted to the acid. That suggest that the tablet only contains 0.588 grams of sodium bicarbonate which is very different from the manufacturers. The second run gave an even smaller number of gram. In terms of moles only .0007 reacted in the first and third run and only .0006 in the second run. There are many factor that could had alter the amount of moles that reacted to the acid which affected the result in showing that there is a smaller composition of sodium bicarbonate in the tablet than that of the manufacturer’s.

Three grams of a mixture containing Benzoic Acid and Naphthalene was obtained and placed in 100 ml beaker and added 30 ml of ethyl acetate for dissolving the mixture. A small amount (1-2 drops) of this mixture was separated into a test tube. This test tube was covered and labelled as “M” (mixture). This was set to the side and used the following week for the second part of lab. The content in the beaker was then transferred into separatory funnel. 10 ml of 1 M NaOH added to the content and placed the stopper in the funnel. In the hood separatory funnel was gently shaken for approximately one minute and vent the air out for five seconds. We repeated the same process in the same manner one more time by adding 10ml of 1M NaOH.

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

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.

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

The purpose of the experiment was to compare antacids by the amounts acid they neutralize to find the most effective antacid. Finding the most effective antacid is important because it will help others by allowing them to choose the best product for their heartburn. Titration is the process of which the unknown solutions concentration reacts with a known solution concentration. During the experiment, titration was used to calculate the moles of HCl neutralized by the antacid in this case was gelusil, by knowing the moles of HCl initially added to the flask and moles of HCl neutralized by the NaOH.

4. Calculate the number of moles of NaOH used in reactions one and two. Show work here and record your answer in Data Table 2.

In this lab a acid-base indicator phenolphthalein was used to determine endpoint of a reaction HCl(aq) and KOH(aq). At the end point all of the HCl(aq) would have reacted with KOH(aq), and the pH becomes 7. The phenolphthalein would changed colours from colourless to pink indication when enough KOH(aq) was added. The purpose of numerous trials was to use the average volume of the 3 trials with similar measurements.

An acid-base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid