Alka Seltzer PDF

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alka seltzer lab...

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Faster Plop, Plop, Fizz, Fizz: A Scientific Method Investigation Student Name:

Mary Kibbe

Date: 02/25/2021

1

Dat Data a Activity 1 1. State a hypothesis for Activity 1 using an “if/then” statement. Remember to create a statement that is able to be tested empirically. If I add an Alka-Seltzer tablet to the hot water, then it will dissolve at a faster rate than the cup with cold water or the cup with room temperature water.

Data Table 1 Run No.

Cup

1

C

1

RT

1 2 2 2 3 3 3 Avg. Avg. Avg.

H C RT H C RT H C RT H

Temp. (˚C)

Time (sec.)

Observations

10

123

20

47

45 12 25 56 7 25

19 102 43 20 116 45

Tablet stays at bottom most of the time. Took some time to dissolve but was not long. Tablet almost immediately floats up. Tablet dances on bottom of cup. Tables moves around cup. A lot of bubbles right away. Fizzing noise. Fizzing noise. Fizzing noise.

51

16

9.6 23.3 50.6

113 45 18

2. Using graphing software such as Excel®, graph the results of Activity 1. Please see the Introduction to Graphing manual for guidance.

See separate page for picture of hand drawn graph.

3. What are the two variables that you graphed? Time (taken to dissolve) and Temperature (of the water) © 2016 Carolina Biological Supply Company

2

4. Which is the independent variable? Should it be on the X- or Y-axis? Why? The Independent Variable is the temperature of the water, which goes on the X axis. The Temperature of the water is controlled though out the lab.

5. Which is the dependent variable? Should it be on the X- or Y-axis? Why? The dependent Variable is the time it takes to dissolve the Alka-Seltzer tablet, which goes in the Y axis because the time the tablet takes to dissolve, depends on the water temperature.

6. Predict how many seconds it will take to dissolve an Alka-Seltzer® tablet in 200 mL of water at the following temperatures. Use the exponential trend line to find the function used in predicting the time. If needed, please refer to the Introduction to Graphing manual for guidance. a. 35°C About 38 Seconds b. 60°C About 9 Seconds c. 80°C About 6 Seconds

Activity 2 7. List five questions about the rate at which Alka-Seltzer® tablets dissolve if the temperature was held constant and one of the controlled variables was changed. 1. What would happen if I added food coloring to each cup? 2. Would the Alka-Seltzer tablet dissolve faster in boiling water? 3. How would the dissolve rate change with 100 mL. of water compared to the 200 mL.? 4. If I constantly stir the water while the tablet dissolves, would the time results change? © 2016 Carolina Biological Supply Company

3 5. If I add salt to the water, then place the Alka-Seltzer tablet in the salty water, how would it affect the dissolving time? 8. Develop a new hypothesis based on one of the questions. Remember that a hypothesis must be testable with empirical or measurable data. If I add 1 tsp. salt to a cup at room temperature, then the Alka-Seltzer tablet will dissolve faster than the cup with ½ tsp. salt and the cup with no salt.

Activity 2 T Ta able

State the hypothesis. Identify the independent variable. Identify the dependent variable. List the controlled variables. How will the dependent variable be measured? If the hypothesis is true, what results are expected?

If I add 1 tsp. salt to a cup at room temperature, then the Alka-Seltzer tablet will dissolve faster than the cup with ½ tsp. salt and the cup with no salt. The amount of water added to the cups of salt. The rate at which the tablet dissolves. Room temperature water, exactly 200 mL. water. How long it takes for the tablet to dissolve to the nearest second. The cup with the most salt added will make the Alka-Seltzer tablet dissolve faster than the others.

© 2016 Carolina Biological Supply Company

4

Dat Data aT Ta able 2 Run No. Cup 1

0 Tsp.

Temp (Celsius) 21

Time (seconds) 50

1

½. Tsp.

21

55

1

1 Tsp.

21

61

2 2

0 Tsp. ½. Tsp.

15 15

94 108

2

1 Tsp.

15

138

3 3

0 Tsp. ½. Tsp.

15 15

66 68

3

1 Tsp.

15

82

Avg. Avg. Avg.

0 Tsp. ½. Tsp. 1 Tsp.

17.3 17.3 17.3

70 77 93.6

Observatio ns Clear water, some bubbles. Water looks hazy. Cloudy/fizz y water. Normal. Took more time to dissolve. Tablet mostly stayed at bottom. Normal. Fizzing at steady rate. Cannot see tablet in water well.

What could have been done in either activity to make the results more reproducible? Although it is difficult, trying to get the water temperatures as close to the same as possible would give more accurate results. So, keeping the cold water at the same temperature so it does not gain any heat from its surroundings and keeping the hot water at the same temperature so it does not cool from its surroundings. © 2016 Carolina Biological Supply Company...