Aspirin Analysis Lab Report PDF

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Aspirin Analysis Dannieca R. Costes Department of Chemistry and Biochemistry, Queens College - CUNY CHEM 1131, 11, Fall 2020! Instructor: Professor. Babak Gandjian

ABSTRACT For this experiment, we learned how to obtain the amount of active ingredients in an aspirin tablet. Our goal was to find the percentage of active ingredient in a 325 mg aspirin tablet. The video showed us that they used an acid-base titration procedure to carefully obtain the proper measurements that will result to the percentage of active ingredients. Through the data obtain from the experiment and what was given to record in the data table 1, we are able to conclude that the percentage average of active ingredient in a 325 mg aspirin tablet through 3 trials is 98.04%.

I.

INTRODUCTION What is an aspirin? Aspirin, also known as acetylsalicylic acid, is a prescription drug used

to relieve and reduce the symptoms of fever, pain or inflammation. Different strengths of aspirin are based on the amount of active ingredients that they contain. The active ingredient in aspirin is acetyl salicylic acid C9H8O4 with a molar mass 180.16 g/mol. Aspirin is an organic compound, it dissolves easily in an alcohol-water mixture. The amount of aspirin in a tablet can be determined by acid-base titration. What is titration? Titration is a way to determine how much acid is in a solution by adding just enough base, of a known concentration, to neutralize the acid. At the point of neutralization, the number of moles of acid (H+) is combined with an equal number of moles of base (OH-). This lab is showing us how to perform a titration by dispensing a base of known volume, which in this case is NaOH (Sodium Hydroxide) and concentration into an acid solution of known volume but with an unknown concentration. The aspirin will be titrated against a standard solution of base, 0.100 mole NaOH. This base will be dispensed from a burette into a beaker containing the dissolved (in ethanol) acetyl salicylic acid, and phenolphthalein indicator, which appears as a faint pink color in basic solutions. The goal of the experiment is to find the amount of active ingredient in aspirin tablet. As we would follow the procedures for the lab, we will physically see the chemical reaction between the two solutions and then will be able to calculate the data to find the amount of active ingredient.

II. EXPERIMENTAL The materials used for this lab are: " •

Ring stand

•

Graduated cylinder

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Mortar and Pestle

•

Funnel

•

Beakers

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Ethyl Alcohol

•

Weighing scale

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Phenolphthalein

•

Clamp

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Aspirin

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Burette

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Water

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Erlenmeyer Flask

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0.100 Molar of NaOH (Sodium

•

Pipette

Hydroxide)"

Step 1: Carefully rinse and clean the burette and pipette by letting the water flow out from both ends. Handle the burette with extreme care due to the length of the burette may prove to be a challenge. Step 2: Rinse the pipette with Ethyl alcohol. Rotate the pipette with your fingertips, allowing the alcohol to clean through it. Let the alcohol flow out from both ends. Step 3: Rinse burette with NaOH. Repeating safety precautions and handling the burette with care due to its length. Let the NaOH flow out from both ends. Step 4: Place the Erlenmeyer flask on the weighing scale. Make sure you press the zero or tare out the scale. Step: 5: Grind an aspirin tablet into a fine powder by using a mortar and pestle.

Step 6: Using the flask on a scale that was prepared in step 4, carefully transfer the aspirin powdered sample to the flask using a funnel placed on top. Then determine the mass in grams, and record it on a data table. The data mass of aspirin is listed on Data Table 1 for trials 1 to 3. Step 7: Add a 10.0 mL portion of ethyl alcohol to the flask and swirl. Step 8: Using a graduated cylinder, measure 25.0 mL of water. Step 9: Add the 25.0 mL of water to the flask. Step 10: Add 3 drops of phenolphthalein indicator into your flask. Then stir the solution with a stirring rod for a couple of minutes until everything has dissolved. Step 11: Fill the burette with 0.100 m NaOH, using a funnel to guide the solution. Make sure there is no bubbles in the burette. Record the initial value of the base and enter it in the data table. Place the burette on the ring stand with a clamp to hold it in place. Step 12: Slowly add NaOH through drops while constantly swirling after it was placed under the burette with a stopcock. Continue doing this until the solution turns a very light pink. Once the solution is light pink, record the volume of NaOH used in the data table. Step 13: Repeat 1-12 for trials 2 and 3, along with recording all data in the data table 1. Calculation step: calculate how many moles of NaOH were needed to neutralize the aspirin solution.

III. RESULTS Data: The lab procedure mentions 3 trials. The data is listed below. Molar mass of acetylsalicylic acid: 180.16 g/mol Molarity of NaOH used: 0.100 m

The NaOH used was 0.100 moles, which equals 0.100 moles per liter.

Data Table 1 Trial 1

Trial 2

Trial 3

Mass of aspirin tablet

325 mg

325 mg

325 mg

Initial Burette Reading

0.00 mL

17.75 mL

30 mL

Final Burette Reading

17.75 mL

35.40 mL

47.65 mL

Volume of NaOH used

17.75 mL

17.65 mL

17.65 mL

Moles of NaOH

1.775 x 10^3

1.765 x 10^3

1.765 x 10^3

Moles of acetylsalicylic acid

1.775 x 10^3

1.765 x 10^3

1.765 x 10^3

Mass of acetylsalicylic acid

320 mg

318 mg

318 mg

Percentage of acetylsalicylic acid in aspirin tablet

98.46%

97.84%

97.84%

IV. DISCUSSIONS Post-lab analysis: Find the average of 3 trials and report the percentage of active ingredient in a 325 mg aspirin tablet. The average of 3 trials is 98.04% of active ingredients in a 325 mg aspirin tablet. (98.46 + 97.84 + 97.84)/3 = 98.04% Aspirin is a weak acid and it partially ionizes in water. It dissolves much more easily in an alcohol-water mixture as shown in the video. It is an organic compound, which also indicates why it can dissolve easily in the alcohol-water mixture. After the acid-base titration experiment was done from the video, you are able to determine the amount of aspirin in a tablet. ! Through my observations of the video, I was left wondering what would happen if the proper precautions weren’t done when the experiment was being done. Such as if the acid-base titration of aspirin was loaded into the flask with an increased amount of NaOH. Could that change the results of the overall experiment. The final burette reading would be off and the

overall trial would be wrong. Then the experiment would have to be done over. This in the long wrong could probably cause a lot of harm to patients that use aspirin. That is why when handling with organic compounds such as aspirin has to be handled with attention and care.

REFERNCES 1. “Aspirin Analysis - Asynchronous Lab” in Chemistry 113.1 Introduction to Chemical Techniques, (Queens College, New York, 2020) 2. “Chemistry Lab - Aspirin Titration” in Aga Villamejor (Youtube, 2013) [Video File] https:// www.youtube.com/watch?v=PTH7xOKY_Co&feature=youtu.be...