Lab 2 - Alka Seltzer Lab Report

Data Analysis Report: Experiment 2. Alka Seltzer Stoichiometry Fabrizio Chigne Valerga Lab Partner: Chris deAngelis Date: 9/23/ Objectives: The goal of this experiment was to understand the behavior of the Alka Seltzer drug and how it differs in percent by mass of NaHCO 3 when different amounts of water and vinegar are used when dissolving it in liquid. Procedures: Procedures followed as written in the lab notebook. Data Analysis and Results: Table 1: Chart that shows the data collected from the lab and the results. # Experiment Run1 Run 2 Run 3 Run 4 Run 5 Run 6 Volume of vinegar (mL)

0 10 20 30 40 50

water (mL)Volume of 60 50 40 30 20 10 Weight of beaker and liquid (g) 169 g 169 g 170 g 170 g 170 g 170 g Weight of Alka Seltzer tablet (g) 3 g 3 g 3 g 3 g 3 g 3 g Weight of beaker, liquid, and tablet (g)

172 g 172 g 173 g 173 g 173 g 173 g

Weight of beaker with all contents after reactionends (g)

171 g 171 g 172. g 172 g 172 g 172 g

Weight loss CO2) (g)(mass of 0 g 0 g 0 g 0 g 1 g 0 g Mass of NaHCO reacted (g) 1 g 1 g 1 g 1 g 1 g 1 g % by mass of the NaHCO3 ina tablet

46 % 46 % 47 % 46 % 61 % 50 %

The table above displays the Alka Seltzer’s behavior and mass of NaHCO3 reacted as well as in % by mass in a tablet. Graph 1:

The graph above shows the mass % NaHCO3 in a tablet of Alka Seltzer when is dissolved with different vinegar amounts.

Run 1: (1 / 3)*100 = 46% Run 2: (1 / 3)*100 = 46% Run 3: (1 / 3)*100 = 47% Run 4: (1 / 3)*100 = 46% Run 5: (1 / 3)*100 = 61% Run 6: (1 / 3)*100 = 50% Discussion Questions:

  1. The limiting reagent is the reagent that is consumed first in a chemical reaction; therefore, it limits the amount of product that can be formed. The graph stays more or less the same regarding the first three trials, but when the vinegar matches the amount of water there is a change. When the limiting reactant changes it increases again and the graph hits its peak. In trial number 2 the limiting reactant is vinegar. If the Alka Seltzer tablet was dissolved in 60 mL of vinegar the percent by mass of the NaHCO3 in the tablet would have been between around 40%. The first great change in the graph was in run #5 when the tablet was dissolved in 40mL of vinegar and only 20mL of water. Later, in run #6 the tablet was dissolved in 50mL of vinegar and 10mL of water and it dropped more than 10%. Since the graph is decreasing and there is no longer water, the next dot would be around 40% if there is run #7.
  2. If HCl was used instead of vinegar it would be more or less the same. The graph would look similar because HCl is a strong acid and vinegar has also acid in its composition.
  3. CO 3 2-(aq) + 2H+(aq)→CO 2 (g) + H 2 O (l)