Brandon Meas Block: B Day 4 Lab day 1 5/12/17 Lab day 2 5/23/17 Lab Day 3 6/2/17
Lab 9: Acids and Bases
Purpose: The purpose of the lab is to calculate the concentration of a known acid. Using the data collected from this lab, you will calculate the molarity of the acid.
Introduction: In chemistry, concentration is the amount of a substance in a given volume of space. Concentration is also the ratio of solute in a solution to either solvent or total
…show more content…
An indicator is something that changes color at a specific pH value or in the presence of a particular substance and can be used to monitor acidity or the progress of a reaction.
You will know you are done with your Titration when the solution completely is indicated a certain color for a long period of time. The amount of OH and H3O at this point will be equal at pH 7.
The mathematical formula used for titration calculations is Macid x Vacid = Mbase x Vbase
Procedure:
During preparation for this lab, measure out 2 to 3 mL of NaOH. Obtain a waste beaker and place it under the burette and make sure the stopcock is closed. Measure out 20 mL of Acetic Acid and pour it into an Erlenmeyer Flask. Add 2 drops of a chemical reaction indicator, Phenolphthalein, to the Acetic Acid. Remove the waste beaker from under the burette and replace it with the Erlenmeyer Flask. From the NaOH in the Burette, add it to the acid milliliter by milliliter. The solution should gradually turn pink. When the solution starts to stay a pink color for a longer period of time, decrease the rate of the dropping of NaOH. Be sure not to overshoot the amount of NaOH. Record the final volume of the NaOH when the solution turns completely pink. Before clean up, put the waste beaker under the burette and drain the remaining NaOH from the burette. Dump the waste into a bigger waste beaker your instructor provides. Pour the Acetic Acid down the drain. Repeat the procedure one more time, and if there is more time, repeat a 3rd time. Repeat clean up
The unknown bacterium that was handed out by the professor labeled “E19” was an irregular and raised shaped bacteria with a smooth texture and it had a white creamy color. The slant growth pattern was filiform and there was a turbid growth in the broth. After all the tests were complete and the results were compared the unknown bacterium was defined as Shigella sonnei. The results that narrowed it down the most were the gram stain, the lactose fermentation test, the citrate utilization test and the indole test. The results for each of the tests performed are listed in Table 1.1 below.
Each subsequent trial will use one gram more. 2.Put baking soda into reaction vessel. 3.Measure 40 mL vinegar. 4.Completely fill 1000 mL graduated cylinder with water.
20.0cm3 of 0.10M ethanoic acid was pipetted into a conical flask. 3. 0.10M sodium hydroxide solution was titrated using phenolphthalein as indicator, until the solution was just turned pink. 4. A further 20.0cm3 of the same ethanoic acid solution was added to the flask and was mixed thoroughly.
collect any gas given off). A timer was needed to time how long the experiment took. The conical flask was then filled with 100cm3 of acid.
Acid-Base Titration I. Abstract The purpose of the laboratory experiment was to determine equivalence. points, pKa, and pKb points for a strong acid, HCl, titrated with a. strong base, NaOH using a drop by drop approach in order to determine. completely accurate data. The data for this laboratory experiment is as follows.
The purpose of this lab is to understand the concepts of pH and buffers and how to make a buffer in the laboratory. Also, how to perform the titration process and identify the values of pKa, equivalence point, and the unknown buffer based on the titration process.
middle of paper ... ... error to my experimental result, I will get the value of 63.27. Final experimental result = experimental value + the overall apparatus error = 62.37 + 0.9 = 63.27 % difference between experimental Mr and value of likeliest value = (62 / 63.27) × 100% = 100% − 97.99% = 2.01% 4.3 Conclusion From the titration process I found the molarity of the sodium hydroxide solution and the relative formula mass of the unknown acid. With further calculations I identified the correct formula of the acid.
Next began adding the bleach to the petri dishes using pipettes. Each petri dish was given a different percentage of contaminant. Again, I set the timer for 5 minutes then counted the number of live brine
This procedure was conducted a total of three times. For each one of the trials the color change and calculations were recorded. The moles of hydrochloric acid neutralized by the unknown sample were found by subtracting the moles of sodium hydroxide (which was back titrated) , from the initial moles of hydrochloric acid. The moles of hydrochloric acid neutralized was then dived by the mass of pre weighed sample to give us the amount of moles of hydrochloric acid neutralized per gram of the unknown
The 50 mL beaker was filled one third of the way with sodium hydroxide. The base was poured into the buret, and the buret was cleaned with it. The contents were spilled out into the sink.
In a 100ml beaker place 50mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved.
The point was signaled by a change in color of an indicator that had been added to the acid solution. Indicator is a substance that has distinctly different colors in acidic and basic media. Phenolphthalein was a common indicator which was colorless in acidic and neutral solutions, but reddish pink was result in basic solutions. Strong acid (containing H+ ion) and strong base ( containing OH ) were 100% ionized in water and they were all strong electrolytes.
The materials I used in this lab were red cabbage juice, red and blue litmus paper, measuring cups, a paper towel, distilled water, vinegar, apple cider vinegar, laundry detergent, lime juice, a pH chart, and finally, a dropper. The first step in this lab report is to take one drop of cabbage juice from the measuring cup and put it into the other measuring cups, or the other 5 liquids, and mix the solution together. Next, using the pH chart, decide the color of the solution and record the results. Third, dip the red and blue litmus paper into all of the measuring cups and place them on a paper towel to determine whether each substance is an acid or base using the pH scale. And finally, record all your results in the data chart putting the number each solution is under “pH”, and putting acidic, basic, or neutral under “effect on litmus
The purpose of this lab was to understand the difference between a strong acid and a weak acid and how that affects its titration curve. We were also asked to estimate the ionization constant of a weak base with the data we collected. The first step of the experiment was to put 50 drops of acetic acid into a small beaker. We then recorded the pH values after 0,10,20,30,40,45,50,55,60, 70,80,90, and 100 drops of NaOH was put in the beaker. The pH was recorded by using pH paper and dipping it into the solution at each increment and then comparing it to the color chart.
Place the dialysis tubing into the cup it corresponds with 11. Fill the first cup with the solution indicated on the outside of it until the solution completely covers the model cell placed inside. 12. After 24 hours remove the dialysis tubing bag from the cup. Once again gently roll it back and forth on a paper towel to remove excess liquid.