Monday, January 7, 2013

Dissolving of Alka-Seltzer

Title: Temperature and the Dissolving of Alka-Seltzer

State the Problem: How will temperature affect the speed at which the Antacid tablet dissolves?

Hypothesis:  If the temperature goes up, then the antacid tablet will dissolve faster because there will be more room for the antacid molecules to go in the water because the water molecules will have more room in between then from the heat.

If the temperature goes down, then the tablet will dissolve slower because there will be less room for the tablet molecules to go in the water because the water molecules will have less room in between them from the lack of heat.

Materials:
  • 500 ml beaker
  • graduated cylinder
  • Vernier temperature probe
  • Computer
  • Logger pro software
  • Vernier computer interface
  • 4 alka-seltzer tablets, stopwatch, hot plate, 5 ice cubes

Procedures:
For the hot water test, you must first fill a beaker with 266 ml of water. Then place the temp probe inside beaker on hot plate, and heat on high until 50ºC. Use the stopwatch to record the amount of time it takes to dissolve. Use the probe to take the temp and record it on the computer by clicking run once the tablet is in the water and clicking stop when it is done dissolving. Also record the temperature and the time in your lab notebook.
For the room temp test, you must first fill a beaker with 266 ml of room temp water and put the probe inside the beaker. Drop one tablet into it and click start. Use the stopwatch to record the amount of time it takes to dissolve. Once it is done dissolving, click stop and the software will have recorded the time and temp. Also record the temp and time in your lab notebook
For the cold water test, you must first fill a beaker with 133ml of water and put 5 ice cubes in it. Stir the ice water for about 30 seconds so the temp evens out. Put the probe in the water and drop the antacid tablet in. Use the stopwatch to record the amount of time it takes to dissolve. Click run and once the tablet is done dissolving, click stop. Record it in your lab notebook. The computer will do it automatically.
For the boiling water test, you must first fill a beaker with 266 ml of water and put it on a hotplate. Put the probe in and wait till it is at 100ºC. Use the stopwatch to record the amount of time it takes to dissolve. Drop the tablet in and click start. Once it is done dissolving click stop. Record the information in your lab notebook.


Data and Analysis:

This picture is showing the logger pro system recording the data for the hot water test. At this moment, the water was at about 100 degrees and getting ready to start cooling.

This picture is showing the logger pro system recording the data for the cold water test. At this moment, the water was at about 4 degrees over a 100 second time span.

This picture is showing the logger pro system recording the data for the room. At this moment, the water was at about 21 degrees.

1.This is the room temperature water and shows that it took almost 50 seconds to dissolve in about 22ºC.

2.This is the cold water and it shows that it took a much longer time to dissolve at a colder temperature. Almost 1 minute 50 seconds. That is much longer than the ones with higher temperatuers

3.This is the graph with the hot water. It was heated to about 50ºC and it took the shortest time for the antacid tablet to dissolve.

4.The boiling water was at about 98ºC and took about 22 seconds to dissolve. It weird because it took longer here than the hot water and this one was hotter.


Conclusion:
The hypothesis was proven correct because it did take a longer time for the tablet to
dissolve in the cold water than the warmer ones. Each time the temperature went up, it took a less amount of time for the tablet to dissolve, except for the boiling water. It took longer for it to dissolve than the hot water even though it was hotter...at least twice as hot. The first 3 tests supported my hypothesis but the boiling water did not and I do not know why. The only variable was the temperature, so we know that my hypothesis was correct because the temperature changed the dissolving time.

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