Alka-Seltzer_Lab_Report

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Apr 3, 2024

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ALKA-SELTZER LAB Introduction Alka-Seltzer is an antacid and pain reliever that contains three active ingredients: aspirin, sodium bicarbonate and anhydrous citric acid (Netdoctor, 2019). It was first introduced in the 1930s and used as medication for pain-related issues such as headaches, as well as stomach-related complaints such as indigestion and heartburn (de Abajo et al, 2009). The sodium bicarbonate is considered to have 3 roles: to neutralize stomach acid (which is how the tablet relieves heartburn), to increase the absorption speed of aspirin (which works as a pain reliever), and to react with citric sodium to produce carbon dioxide (de Abajo et al, 2009). Because of its versatility, it was once considered to be a cure all, but studies have shown that it can have adverse side effects including dizziness/passing out, kidney problems and liver problems if taken often. Because of this the drug has been mostly depopularized though it is still accessible over the counter (Netdoctor, 2019). When the tablets a immersed in water, which is how they are usually taken, the carbon dioxide that is released from sodium bicarbonate bubbles out of the liquid. The carbon dioxide lost can be measured and the amount of sodium bicarbonate originally present in the tablet can be determine. In this lab, we will be evaluating the consistency of the percentage of sodium bicarbonate in the tablets. MATERIALS AND METHODS 4 Alka-Seltzer tablets were obtained and each tablet was weighed and had its mass recorded. One clean, dry 250mL glass beaker was weighed as well and the mass recorded. After this, 25mL of vinegar was added to the 250mL beaker using a 25mL graduated cylinder. The beaker containing 25mL vinegar was

then weighed and recorded. One tablet was then added to the beaker with the vinegar. About 3-4 minutes after the fixing stopped, the beaker was gently tilted from side to side in a circular motion to react any still powdered Alka-Seltzer that may have been on the sides of the beaker. This was done for the remaining 3 tablets as well. Between trials, the beaker was rinsed out, dried, and reweighed. The RESULTS Table 1.1 Trial Mass of Tablet (g) Mass of beaker (g) Mass of beaker & vinegar Mass of beaker, vinegar and tablet (g) Mass after bubbling ceases (g) Mass of CO2 lost (g) I 3.2505 121.0862 144.3075 147.558 146.5376 1.0204 II 3.3517 121.0787 144.0439 147.2956 146.2947 1.0009 III 3.2780 120.1985 144.2555 147.8330 146.1369 1.6961 IV 3.2879 121.0886 144.9527 148.2406 147.1245 1.1161 Table 1.2 Trial Mass CO2 lost (g) Mass of NaHCO3 (g) Mass of Tablet (g) %NaHCO3 in Tablet I 1.0204 1.9480 3.2505 59.93 II 1.0009 1.9108 3.2517 58.76 III 1.6961 3.2380 3.2780 98.78

IV 1.1161 2.1307 3.2879 64.81 Average 1.2084 2.3069 3.2670 70.57 Standard Deviation 0.3290 0.6281 0.0188 18.99 Table 1.3 Trial Mass CO2 lost (g) Mass of NaHCO3 (g) Mass of Tablet (g) %NaHCO3 in Tablet I 1.0204 1.9480 3.2505 59.93 II 1.0009 1.9108 3.2517 58.76 IV 1.1161 2.1307 3.2879 64.81 Average 1.0458 1.9965 3.2634 61.17 Standard Deviation 0.0617 0.1177 0.0213 3.205 The data collected for this experiment was recorded in Table 1.1 and Table 1.2. The mass of NaHCO 3 in each tablet was calculated using the equation: mass of CO 2 lost x molar massNaHCO 3 molar massCO 2 = mass NaHCO 3 in tablet

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The percentage NaHCO 3 present was calculated again using the equation: % NaHCO 3 = mass NaHCO 3 original massof tablet x 100 DISCUSSION The goal of this lab was to evaluate the consistency of the percentage of sodium bicarbonate in a few Alka-Seltzer tablets. The experiment went well and yielded expected results, with only one possible error for Trial III which yielded a 98.78% of NaHCO 3 , which was much higher than the rest of trials. This could have been caused by an incomplete reaction between the tablet and the water upon weighing. Basing on Trials I, II and IV (Table 1.3) which were more precise, we found that the percentage of sodium bicarbonate was not exactly consistent but did fall in the same range which was 59-65%. The standard deviation was fairly low (3.205), indicating that our results were clustered around the mean of 61.17%. The results of the experiment could have been better if the Alka-Seltzer tablets were left in the water for a longer period of time to ensure that all of the powdered Alka-Seltzer reacted before weighing. The lab could have also been more informative if more than four trials were taken. CONCLUSION The percentage of sodium bicarbonate in a few Alka-Seltzer tablets is not consistent but varies per tablet. However, the variations seem to be clustered around a mean value. REFERENCES

de Abajo, F.,J., & García Rodríguez, L.,A. (2009). The continuing unacceptable marketing of alka-seltzer [trademark] containing aspirin for stomach-related disorders: An international journal of medical toxicology and drug experience. Drug Safety, 32 (7), 619-21. doi:http://dx.doi.org/10.2165/00002018-200932070-00008 Netdoctor (2019, June 17). Alka-Seltzer Original . Netdoctor. Retrieved November 12, 2021, from https://www.netdoctor.co.uk/medicines/aches-pains/a8379/alka-seltzer-original/.