Experiment No. 1
Analysis of Stomach Antacid Tablet
A LABORATORY REPORT
Presented to the Faculty of the Department of Chemistry College of Science and Mathematics University of Science and Technology of Southern Philippines
In Partial Fulfillment of the requirements in INDUSTRIAL CHEMISTRY 2 LABORATORY
Baytion, Ana Margarita L. Estrella, Rochelle P.
Date of Experiment: November 29, 2017
CHAPTER 1 INTRODUCTION
1.1 Background of the Study Some of the most important processes in chemical and biological systems are acid- base reactions in aqueous solutions (Chang, 2010). An acid –base reaction is a chemical reaction that occurs between an acid and a base neutralizing the acid and base properties, producing a salt. In a healthy stomach, pH is regulated naturally and digestion functions properly when the pH is around three. Excess stomach acid can be combated with bases, or antacids. Anatacids are bases that reacts stoichiometrically with acid, they are H+ acceptors and in water, they provide species that can react with H+. The common ingredients in antacids are m etal hydroxide and metal carbonate salts. The hydroxide ion reacts with H + forming H2O and carbonates provide carbonate ion CO 3 2- which can react with H + to form H2O and CO2. H+ (aq) + OH- (aq) → H2O (l) 2H+ (aq) + CO3 2- (aq) → H2O(l) + CO2 (g) In this experiment, the number of moles of stomach acid that can be neutralized by a commercial antacid tablet was evaluated. Since stomach acid is largely HCl, thus the neutralization reaction between HCl and the active ingredients of the antacid tablet, Mg(OH) 2 and Al (OH)2 is represented by: Mg(OH)2 + 2HCl ↔ Mg2+ + 2Cl- + 2H2O Al(OH)2 + 2HCl ↔ Al2+ + 2Cl- + 2H2O Furthermore, titration method was used in order to compare the antacid activity between sodium bicarbonate and a commercial antacid tablet by comparing the moles of HCl neutralized per g antacid.
1.2 Objectives of the Study a. To determine the amount (number of moles) of stomach acid that can be neutralized by a commercial antacid tablet b. To compare the antacid activity between sodium bicarbonate and a commercial drug (Kremil-s) in treating hyperacidity
CHAPTER 2 METHODOLOGY Two antacid tablets were crushed using a mortar and pestle. The crushed tablet was then weighed and then divided equally to three 250-mL Erlenmeyer flask. Exactly 100-mL of 0.10 M HCl was added to each flask dissolving the crushed tablet. Furthermore, 5 drops of bromophenol blue solution was added to the flasks. If the solution did not turn to yellow, additional 0.1 M HCl in 10-mL increment was to be added until yellow. The solutions was then titrated against the standardized NaOH and the appearance of a blue colored solution indicated the end of titration. Lastly, the volume of NaOH required to neutralize the excess acid was recorded. The same procedure was used for the titration of 0.70 g of sodium bicarbonate. .
CHAPTER 3 RESULTS AND DISCUSSIONS
3.1 Raw Data Kremil-s contains: 178 mg Al(OH) 3, 233 mg Mg(OH)2, 30 mg Simeticone; at 6php. Two (2) tablets of Kremil-s used for three trials. Table3.1 Determination in Volume of Base used to Neutralize Acid with Kremil-s by Titration Method Trial No. 1 2 3
Mass of Volume of Drops of Initial vol of Final vol of Total vol of Kremil-s, g HCl, mL Indicator NaOH, mL NaOH, mL NaOH, mL 0.5135 77.0 5 0 3.9 3.9 0.5589 77.0 5 3.9 7.0 3.1 0.5556 77.0 5 7.0 11.6 4.6 This table showed the volume used for sodium hydroxide in order to neutralize hydrochloric acid with the help of an antacid (Kremil- s). Kremil-s contained more than one base, the alum inum hydroxide and magnesium hydroxide, which helped to neutralize the acid. For the three trials made, the volume used was in the range of 3.1-4.6 mL of NaOH. However, there was no trend or relationship observed between the volume of NaOH and the mass of Kremil-s and this might because of the titration method made to achieve the blue color.
Table3.2 Determination in Volume of Base used to Neutralize Acid with Soda by Titration Method Trial No. 1 2 3
Mass of Volume of Drops of Initial vol of Final vol of Total vol of Soda, g HCl, mL Indicator NaOH, mL NaOH, mL NaOH, mL 0.7050 100 5 11.6 21.7 10.1 0.7023 100 5 21.7 32.9 11.2 0.7180 100 5 32.9 43.2 10.3 Shown in this table the volume used for sodium hydroxide in order to neutralize hydrochloric acid with the help of a single antacid (sodium bicarbonate; soda). These values will be compared to the results obtained from the neutralization calculated in Table 3.1. This will determine which will be a better antacid: a single base or a combination of two bases in order to neutralize an acid.
3.2.1 Calculation for the moles of HCl neutralized by antacid and sodium bicarbonate The moles of HCl neutralized by the antacid can be calculated with this equation: moles HCl = (MV)HCl – (MV)NaOH where MHCl is the concentration of the HCl solution, V HCl is the volume of HCl used to dissolve the tablet, MNaOH is the concentration of the NaOH solution, and VNaOH is the volume of NaOH used to neutralize the acid. Sample Calculation For Trial 1 (Kremil – s): moles HCl= [(0.1M)(0.100L)] – [(0.1M)(0.0039)] = 9.61 × 10-3 moles
3.2.2 Calculation for the moles of HCl consumed by gram of antacid and sodium bicarbonate The moles of HCl consumed by a specific gram of antacid can be calculated by: moles/g = moles HCl/ g antacid Sample Calculation For Trial 1 (Kremil – s): moles/g = moles HCl/ g antacid = 9.61×10-3 moles/ 0.5135 g = 0.012751773 moles/g
3.3 Summary of Results Table3.3 Calculated Results for the moles of HCl consumed per gram of antacid (Kremil-s) Trial No.
Mass of Kremil-s, g
Total vol of NaOH, mL
Moles of HCl neutralized
1
0.5135
3.9
0.00961
Average Moles of HCl neutralized
Moles HCl/g antacid
Average moles/g
Standard Deviation
0.018714703
2 3
0.5589 3.1 0.00969 0.009613333 0.017337627 0.017740986 0.000847388 0.5556 4.6 0.00954 0.017170626 Shown in this table the moles of hydrochloric acid neutralized per gram of the antacid used. It was calculated that for two tablets of Kremil-s used, it neutralized an averaged 0.00961 moles of HCl. So for the three trials, an average of 0.0177 moles/g of antacid were neutralized. Moreover, results obtained were precise that was proved by a lower standard deviation.
Table3.4 Calculated Results for the moles of HCl consumed per gram of antacid (sodium bicarbonate) Trial No. 1 2 3
Mass of Soda, g
Total vol of NaOH, mL
Moles of HCl neutralized
Average Moles of HCl neutralized
Moles HCl/g antacid
Average moles/g
Standard Deviation
0.7050 10.1 0.00899 0.012751773 0.7023 11.2 0.00888 0.008946667 0.012644169 0.012629659 0.000129977 0.7180 10.3 0.00897 0.012493036 This table also showed the moles of hydrochloric acid neutralized per gram of soda used. The results obtained were used in comparing the antacid activity of the commercial drug (Kremil-s). As shown, Kremil-s neutralized more hydrochloric acid than sodium bicarbonate based on their averaged moles consumed. It also showed that Kremil-s consumed more acid by the results calculated in moles HCl/g antacid than sodium bicarbonate.
CHAPTER 4 CONCLUSION
This experiment aims to compare the antacid activity of a commercial drug in treating hyperacidity, Kremil-s, between sodium bicarbonate. Kremil-s composed of 178 mg Al(OH)3 and 233 mg Mg(OH) 2 that can be bought only at a low price. Compared to sodium bicarbonate, Kremil-s has obviously more basic properties. Results showed that the antacid activity of Kremil-s as a neutralizing agent to an acid was better that a single base. This indicated that Kremil-s is a good treatment when having hyperacidity because it neutralized more acid in the stomach directly. Thus, two or more bases were needed to neutralize eff ectively stomach hyperacidity.
REFERENCES
[1] Lab 4 - Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration. Retrieved from http://www.webassign.net/question_assets/ucscgencheml1/lab_4/manual.html [2] Change, R. (2010). Chemistry (p.659) New York; McGraw-Hill Companies, Inc.
