Dissolving with Different Alka Seltzer® Structures

Dissolving with Different Alka Seltzer® Structures

By:Teresa Tran

Period:3

Date: 15 December, 2015

Future Research

To learn more about the topic of dissolving doing the experiment over with changing the variable of the temperature of the water can be another experiment to try. With the knowledge gained from the experiment Alka Seltzer® companies should have before hand made Alka Seltzer® powder packets to have quick dissolving for the customer.

Conclusion

The hypothesis was supported in the experiment because the average for a whole tablet was 165 seconds, the tablet cut in half 124 seconds, the tablet cut in quarters is 84 seconds, and the crushed tablet is 56 seconds.The major findings of the experiment demonstrated the more pieces the tablet is broken up into the faster the tablet will dissolve. Some of the errors throughout the experiment that could have occurred include timing, uneven tablet sizes, and inconstant stirring.

Table

Results

Graph

When the Alka Seltzer was dissolving it formed fizzing bubbles. The bubbles are made out of CO2. This is known as a chemical reaction. The bicarbonate had reacted to the hydrogen in the water to form the CO2 bubbles.

Procedures

Average Graph

• Measure the water to 100 mL and fill the cup
• Start the stopwatch/timer when the tablet starts bubbling to the end of the bubbling
• Scrape the tablet into the clear cup filled with water
• constantly stir the water in a constant speed to speed the experiment up.
• Whole tablet: Left alone to test
• Halves of the Tablet: Cut the tablet in half use both pieces for the trials
• Quarters of the Tablet: Cut the tablet in quarters and use all the pieces for the trials.
• Crushed Tablet: Crush the tablet into fine pieces to scrape into the cup for the trials
• Total of 20 trials

Materials

• 20 Alka Seltzer Tablets®

• 80 ºF Sink/tap water that went through a water softener

• Clear small Cup

• Measuring cup for water

• Stop Watch or Timer

• A small plastic cutting board

• Stick or something to stir with

• Knife to cut the tablet

Hypothesis

Research

The hypothesis of the experiment is “If the tablet’s structure is broken into more pieces, then the dissolving time will be shorter because the more pieces the Alka Seltzer® is broken up into, the more surface area will be exposed for the reaction to occur.”

• The more surface area the tablet has the more reaction area the chemical reaction can occur.
• The main ingredients of Alka-Seltzer tablets are aspirin, citric acid, and sodium bicarbonate (NaHCO3).
• When sodium bicarbonate dissolves in water, it splits apart into sodium (Na+) and bicarbonate (HCO3−) ions.
• Then bicarbonate reacts with hydrogen ions (H+) from the citric acid to form carbon dioxide and water.

Problem

The problem of the experiment is “What is the effect of Alka Seltzer® structure on the dissolving time?”

Independent Variable: The tablet structure

Dependent Variable: The time it takes to dissolve

Control Variable: The temperature of water, constant stirring, type of water, and type of cup.