How should customers take their Alka-Seltzer?

The findings of 2-3 B

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

Variables tested

• 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

• 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?

• Hypothesis: We believed that the Alka-Seltzer tablet would dissolve quicker as it was stirred faster

Stirred vs. Not stirred (Group 1)

Speed

Not stirred Slow Fast

Trial 1 (s) Trial 2 (s) Trial 3 (s) Average (s)

56.8

45.4

Medium 41.5

40.5

52.4

46.9

44.9

37.9

54.2

44.6

43.2

41.9

54.5

45.6

43.2

40.0

Standard Deviation

2.212088

1.167619

1.7

2.003331

Data

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

60

Time to dissolve stirred at a certain speed

50 20 10 40 30 0 Not stirred Slow Medium

Stirring Speed(setting)

Fast

Graphical Analysis

• 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

•

Hypothesis: The warmer the tablet, the quicker it will dissolve in the 50mL of water.

Temperature of tablet (Group 2)

Temperature of tablet (˚C) Time (s)

5.6

60.65

14 20.7

55 46.07

46 112 37.26

14

Data

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.

70

Temperature of tablet vs. time to dissolve

60

T i m e

50 40

s e c o n d s

30 20 10 0 0 20 40 60 80

Temperature (degrees Celsius)

100 120

Graphical Analysis

• 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

• 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)

Type of liquid Time (trial 1) (s) Time (trial 2) (s) Time (trial 3) (s) Average (s) Standard Deviation

Distilled Water Coffee 48.4

175.7

Diet Pepsi 55.3

Cranberry Juice 62.8

Data

46.8

180 61.6

56.9

53.2

171.2

57.2

68.9

49.5

176 58 62.9

2.719477074

3.592894222

2.638602324

4.899206285

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

Alka-Seltzer dissolving time in liquids

200 180 160 140 120

Time to

100

Dissolve

80

(s)

60 40 20 0 Controlled distilled water Coffee Diet Pepsi Cranberry juice

Type of Liquid

Graphical Analysis

• • • 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

•

Hypothesis: We believe that as the amount of water increases, the Alka Seltzer tablets will dissolve quicker.

Volume of water (Group 4)

Amount of water (mL) Time (trial 1) (s) Time (trial 2) (s) Time (trial 3) (s) Average (s) Standard Deviation

20 50 100 200 65.7

52.8

49.1

54.6

Data

58.7

51.4

52.1

50.8

69.8

57.6

50.8

48.2

64.7

53.9

50.7

51.2

5.613

3.252

1.504

3.219

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

30 20 10 0 70 60 50 40

Dissolving Time in Different Amounts of Water

20 50 100

Amount of Water (mL)

200

Graphical Analysis

• 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

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)

Data

Dissolving Time For Different Size Alka-Seltzer Tablets

30 20 10 0 70 60 50 40 Half Tablet 0.25 Tablet 0.125 Tablet

Size of Tablet

Graphical Analysis

Powder After Powder First

• • • 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

• 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)

Temperature of Water ( o C) Time (Trial 1) (s) Time (Trial 2) (s) Average (s) Standard Deviation 19.3

8.6

30.3

60.4

109.7

36.4

64.0

108.9

39.9

62.2

109.3

38.15

1.8

0.4

1.75

Data

• Lowest temperature: highest time (~110 seconds) 120,0 100,0

Temperature of Water vs. Dissolving Time

80,0 • Room temperature: 60,0 40,0 • average time (~62 seconds) 20,0 • Highest temperature: lowest time (~38 seconds) 0,0 19,3 8,6

Temperature of Water (˚C)

Graphical Analysis

30,3

• 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

• 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