How should customers take their Alka-Seltzer?

1. How should customers take their Alka-Seltzer? The findings of 2-3 B

2. Stirred vs. not stirred • Temperature of tablet • Volume of water • Substances • Surface Area • Temperature of water Variables tested

3. 50 mL of water • Distilled water • Room temperature tablet and water • no stirring • half tablet • stop the time when tablet itself has stopped dissolving Constants

4. Effervescence: • Citric acid and baking soda in the tablet go through a chemical reaction • The final product is water, carbon dioxide, and sodium citrate • The sodium citrate is dissolved in the water • That’s the gas we see being emitted from the tablet. What happens in an Alka-Seltzer reaction?

5. Hypothesis: We believed that the Alka-Seltzer tablet would dissolve quicker as it was stirred faster Stirred vs. Not stirred (Group 1)

6. Data

7. The graph shows that as the stirring speed increased, the time to dissolve decreased. Graphical Analysis

8. The data collected does accurately support the hypothesis in that the time to dissolve decreased as it was stirred faster. • Experimental Difficulties • measuring exactly 50 mL of water • cutting exactly half a tablet • perfectly accurate timing • Future Improvements • more accurate stopwatch • set of tablets equal to half a normal tablet • the same person timing and watching the tablet dissolve Analysis

9. Hypothesis: The warmer the tablet, the quicker it will dissolve in the 50mL of water. Temperature of tablet (Group 2)

10. Data

11. The tablet with a greater temperature dissolves faster because the particles in the tablet are moving faster, causing a quicker reaction when coming in contact with water. Graphical Analysis

12. Overall, our hypothesis was correct that the greater the temperature of the tablet, the quicker the tablet would dissolve after coming in contact with the water. • Experimental Errors • Amount of Water • Tablet not cut exactly in half • Don't know exactly when tablet is fully dissolved • Ways to Improve • Use full tablet as constant to all are exact same size Analysis

13. Hypothesis: The Alka-Seltzer tablet will dissolve faster in other liquids than in distilled water, especially in a carbonated drink. Type of Liquid (Group 3)

14. Data

15. The graph shows the time for the tablet to dissolve in different liquids. Graphical Analysis

16. The data that we collected with this experiment did not support our hypothesis that the controlled type of liquid would dissolve the tablet the slowest. • Experimental Errors •  Timing exactly • Correct measurements of liquids and tablets • Warming the soda took away the carbonation • Future Improvements •  Whole tablets, no error on cutting • More accurate timer • The liquids all at room temperature before experiment started Analysis

17.  Hypothesis: We believe that as the amount of water increases, the Alka-Seltzer tablets will dissolve quicker. Volume of water (Group 4)

18. Data

19. The graph shows the relationship between the amount of water and average dissolving time. Graphical Analysis

20. The results we found roughly supported our hypothesis that as we got more water, the tablets would dissolve quicker. But really, the difference in average dissolving time was ten seconds at the most -- so there wasn't any significant changes to dissolving time as we changed the amount of water. • Experimental Errors • When we ended timing ("when the tablet was fully dissolved") had a lot of room for judgment and human error. • Our measurements of the amount of water for our tests could be slightly off. • We might of not cut the tablets perfectly in half therefore changing a variable (size of tablet) • Room for Improvement • We could have measured all other variables so we were sure they met control conditions. (i.e. temperature of water, size of tablet) • We could have been more accurate timers. Analysis

21. Hypothesis - We predict that the Alka-Seltzer tablet will dissolve faster when crushed into a powered form and then pouring the distilled water. Surface Area of tablet (Group 5)

22. Data

23. Graphical Analysis

24. The data we collected does support our hypothesis which was that putting the crushed tablet first and then pouring the water would decrease the time it took to dissolve the tablet. • Experimental Error • Accuracy of measuring 50 ML into a beaker • Cutting a tablet into halves, quarters, and eights, and crushing the tablet • Accurate timing • Future Improvements • More accurate stopwatch • Using whole tablets • Having the same person look watching the tablet dissolve Analysis

25. The tested variable was the temperature of the water. We used the control temperature (19.3 ˚C), hot water (30.3 ˚C) and cold water (8.6 ˚C) • Hypothesis: The Alka-Seltzer tablet would dissolve the fastest in the hottest water. Temperature of Water (Group 6)

26. Data

27. Lowest temperature: highest time (~110 seconds) Room temperature:  average time (~62 seconds) Highest temperature: lowest time (~38 seconds) Graphical Analysis

28. We found that the higher the temperature of water, the quicker the tablet dissolves in the water. • This matches our hypothesis completely. • There was only one major difficulty in our experiment. It was very difficult to get the water to be at the same temperature for two separate trials.  • Things we could change for future experiments include making our temperatures precise, and also experiment with a greater range of temperatures (i.e. 10 ° C, 20 ° C, Room Temperature, 30 ° C, etc.) Analysis

29. Through the results of this experiment, we have found that the most efficient method to use Alka-Seltzer would be using the fastest results from all experiments, provided they are safe and practical. • One should: • Stir it fast (difference of 14.5 seconds)* • Make it a powder before putting the tablet in (36.3 seconds) • Put it in hot water (24 seconds) • Put it in water** • Put it in a large amount of liquid (13.5 seconds) Conclusion *in comparison to control **water was the control