Testing the effect of temperature on
the rate of the reaction of Alka-Seltzer in water
For this experiment, it was attempted to discover how the rate of the reaction of Alka-Seltzer in water would be affected when the Alka-Seltzer tablets were added to waters of different temperatures. Alka-Seltzer is made up mainly of Sodium Bicarbonate and citric acid. When this tablet is dropped into the water, both the acid and the sodium bicarbonate dissolve into the water and react with one another, which is what causes the fizz. The products of this reaction are water, carbon dioxide, and sodium citrate. Because it is known that heating up particles increases their kinetic energy and therefore their collision force, it is hypothesized that as the temperature of the water is raised, the rate of the reaction of Alka-Seltzer in water will increase.
• 6 Alka-Seltzer ...view middle of the document...
Drop in the Alka-Seltzer tablet, and at the same time start the stopwatch.
4. Monitor the reaction. As soon as the tablet has completely dissolved, stop the stopwatch and record your data.
5. Dispose of the solution, and begin the process with a beaker of fresh deionized water. Repeat steps 1 through 4 with the other five tablets, increasing the temperature of the water 10 degrees Celsius each time.
Effect of temperature on the rate of the reaction of Alka-Seltzer
|Temperature |30˚C |40˚C |50˚C |60˚C |70˚C |80˚C |
|Time |33.47s |22.81s |17.47s |17.84s |19.22s |22.04s |
In figure 1, these data show the effect of temperature on the speed the Alka-Seltzer tablet dissolves. These data show that as the temperature increases below 60 degrees Celsius, dissolve time decreases. However, as temperatures increase above 60 degrees Celsius, dissolve time increases.
These data show that as the temperature of the water went up, the speed the Alka-Seltzer tablet dissolved went down, until the temperature went past 60˚C. These data show that the hypothesis of time decreasing as the temperature increases was false. One explanation for this result could have been from the increased amount of fizz and bubbles. When the temperature increases the amount of fizz that the tablet produces increases. The fizz from the tablet jumps up out of the beaker until the tablet is gone. With the increase of fizz, the amount of bubbles that form and the amount of fizz jumping increases. Therefore, less amount of water will come intact with the Alka-Seltzer tablet, decreasing the speed of reaction.
In this lab many sources of error could have occurred. First, using different amounts of heat could change your data by changing the rate the water gets heated. Second, if your tablet gets stuck to the side of the beaker on some trails and not the others, the tablet would not be exposed to the same amount of water. Finally if you did not properly wash your beaker after a trial, the excess liquid could decrease the rate of reaction of the next trial. For future experiments more trials could help clarify the data.