A Back-titration Lab Report

Antacid Analysis: A Back-Titration I. Introduction The purpose of this experiment was to explore the effectiveness of two different commercial antacids. Antacids are tablets that are taken when a person has indigestion problems, which are caused by an excess of stomach acid. When someone has excess acid, the pH of the stomach changes which then leads to irritation of the stomach lining and upper intestinal tract. To determine the most effective neutralizer of dilute acid, we took two different antacid tablets and performed a back-titration. II. Data, Results, and Evidence Procedure The procedure was used as received. Worksheets and Figures Tables. Table 1. Antacid Information Antacid Tums Gaviscon Cost of Number of Bottle ($) Tablets Per 4.29 6.98 Bottle 72 100 Active Ingredient Mass of One Dose (g) Calcium Carbonate Aluminum 6.92 4.84 Hydroxide and Magnesium Carbonate Table 2. Tum Flasks Masses (grams) Flask 1 Flask 2 Flask 3 Initial: 109.05 98.96 105.79 After Antacid is Added: 111.07 100.76 107.02 1 Table 3. Gaviscon Flask Masses (grams) Initial: 126 133.20 128.41 Flask 1 Flask 2 Flask 3 After Antacid is Added: 127 134 129.77 Initial Concentration of NaOH: 0.121 M Initial Volume of NaOH: 49 mL Initial Concentration of HCl: 0.0121 M Initial Volume of NaOH: 49 mL 35 mL was added to each flask to change the solution from light yellow to a shade of pink. Table 3. Trials of Tums Trial 1 Trial 2 Trial 3 Initial Color: Salmon Pink Salmon Pink Pale Pink Final Color: Lemon Yellow Lemon Yellow Lemon Yellow NaOH Used (mL): 14 13 11.7 Final Color: Light Yellow Light Yellow Light Yellow NaOH Used (mL): 32 31.5 32 Table 4. Trials of Gaviscon Trial 1 Trial 2 Trial 3 Initial Color: Hot Pink Hot Pink Hot Pink Calculations Equation 1: Average of 3 Trials Tums: = 12.9 12.9*3 = 38.7 mL Gaviscon: = 31.8 2 31.8*3 = 95.4 mL Equation 2: Initial HCl Amount (mol) Equation 3: HCl Remaining (mol) Tums: Gaviscon: Equation 4: Amount of HCL Neutralized (mol) Tums: 0.0121 – 0.00468 = 0.11632 mol HCl Gaviscon: 0.0121 – 0.00115 = 0.11985 mol HCl Equation 5: Cost-Effectiveness Tums: Gaviscon: Equation 6: Mass Effectiveness Tums: 3 Gaviscon: III. Analysis of Evidence or Discussion This experiment aimed to find which antacid tablet would be the best neutralizer by performing a back-titration. Before we performed a back-titration, we found which antacid would be the most costeffective. Tums were 4.29 dollars for 72 tablets and Gaviscon was 6.98 dollars for 100 tablets. That means one would pay around 0.86 cents per gram for Tums and 1.44 dollars per gram for Gaviscon. This would mean that Tums is the more cost-effective antacid. To determine which antacid was most effective at neutralizing acid, we had to determine the moles of HCl that were neutralized and divide them by the grams of one dose. For Tums, we calculated that it was 0.0168 mol/g and for Gaviscon, it was 0.0248 mol/g. Since Gaviscon has a higher number of moles per gram, it is then the most effective at neutralizing acid. Errors may have happened due to several reasons such as possible contamination of tablets, adding HCl too early, or just human error with calculations. Other factors that should be included when picking an antacid tablet, is the active ingredient and the nature of one’s symptoms. For acid reflux, a person would want a product that contains alginate combined with either calcium, aluminum, or magnesium, calcium carbonate, aluminum hydroxide, or magnesium hydroxide/carbonate. For a sour stomach, a person would want calcium carbonate, aluminum hydroxide, magnesium hydroxide.1 How long one person wants relief for too plays a part. Some antacids can work up to 12 hours of relief, while others may be short-term solutions. IV. Claims We claim that Gaviscon was the most effective in neutralizing acid based on our observations. The back-titration experimentally determined this, and from there based on moles per gram, decided that 4 between Gaviscon and Tums, Gaviscon was the better option. However, we also claim that Tums is the more cost-effective out of the two. 5