Reaction Rates Portfolio Worksheet

Question

In this portfolio, you will investigate the effect of temperature and reactant concentration on the rate of chemical reactions. You will conduct two experiments, analyze your data with graphs, and explain the chemical reactions with evidence. Read the directions and review the key words for these lessons.
Part 1: Perform the Temperature Experiment
In this part of the portfolio, you will gather your materials and perform the first experiment, which involves temperature and reaction rate.
Step 1: Gather Materials
Gather the following materials for this experiment. When you are done with this experiment, set the materials aside. You will use them again in the experiment for Part 3.
clear 12-ounce plastic cups (7 cups total)
effervescent antacid tablets (1 package)
hot and cold tap water
ice cube(s)
marking pen
pen or pencil
sheet of graph paper
stopwatch or a watch or clock with a second hand
thermometer
 
Step 2: Perform the Temperature Experiment
Follow the step-by-step procedure to conduct your experiment. Record and describe your data. You will use this data for Part 2. Step-by-Step Procedure
Here is the step-by-step procedure.

Label one cup Hot Water, the second cup Ice Water, and the third cup Room Temperature Water.
Turn on a faucet and run the tap water until it is very hot. Fill the first cup about "3" /"4" full of hot water.
Use the thermometer to take the temperature of the water. Record your data.
Drop one antacid tablet in the water. Measure the time it takes for the tablet to completely dissolve and stop fizzing. Record the time.
Fill the second cup about 1/2 full of room temperature water. Add the ice cube(s) to bring up the water level so the cup is about 3/4 full. Wait about 15 seconds for the temperature in the cup to come to equilibrium. The water should be cold.
Repeat Steps 3 and 4. Record your data.
Fill the third cup about 3/4 full of room temperature water.
Repeat Steps 3 and 4. Record your data.

Record Data and Notes
Record your data from the procedure. You can record your data with any method you choose, but a table is provided as a starting point. If you use another data collection method, remove the table and insert it here. If you noticed anything during your investigation you want to document, use this space to jot down any notes or additional observations. (If needed, add more rows or columns to the table.)

Data Hot Water Cold Water Room Temperature Water
Temperature
Time to Dissolve
Notes/ Observations

 
Part 2: Analyze the Temperature Experiment
Graph the data you collected in Part 1 and analyze it to understand the effect of temperature on reaction rate. Once your graph is complete, answer the questions that follow.
Step 1: Graph Your Data
Create a line or bar graph of temperature versus reaction time using the data from all three cups. Make sure your data is accurately represented. Note: Insert your data here.

 
Step 2: Questions
Review the data from the temperature experiment and the graph you created. Examine the results, and then answer the following questions to analyze the results. (Add additional space as needed for any item.)

What is the independent variable?

What is the dependent variable?

Analyze the data. Are there any statistical features in your data, including any patterns, sources of error within the study, or any limitations that may have impacted your research? What are they? How could they impact your research? Explain your response.

Suggest an everyday activity that will mirror your results of this activity.

This question has two parts.
What quantitative relationships were present in your data?

What mathematical calculations were needed before you could draw conclusions? Provide an example.

Notes
If you noticed anything during your investigation you want to document, use this space to jot down any notes or additional observations.

 
Part 3: The Concentration Experiment
To investigate concentration versus reaction rate, you will need some additional materials, which you should already have set aside from Part 1. Gather your materials and review the items. Specifically, you should ensure you have the following materials
the remaining materials you used in the activity from Part 1, including:
clear 12-ounce plastic cups (4)
fresh antacid tablets from your package (4)
Step 1: Plan and Conduct Experiment
Plan and Write Your Procedure
Now, you will create a step-by-step procedure for the second experiment. Review the procedure from Part 1 to understand how to describe the data and the collection methods you will use. You should be as detailed as possible.

. In this experiment, you need to decide what evidence and facts you need to collect. It may help you to think about the scientific principles. Answer the following questions and write out your procedure. (Add additional space as needed for any item.)

What evidence and facts do you need to collect?

What are the independent and dependent variables? Remember that data you collect is the dependent variable.

How will you measure the reactant concentration? It’s important to think about this now because you will graph your data.

What are the steps in your procedure? Describe them.

Record Data and Notes
Now, you will conduct your experiment and record your data. You can record your data with any method you choose, but the table in Part 1 is provided for you as a starting point. You may need to update the heading columns. If you notice anything during your investigation you want to document, you can also use this space to jot down any notes or additional observations. (Add additional space as needed.)

 
Step 2: Graph Your Data
Create a graph of your results using the data from the experiment. Note: Insert your data here.

Remember to label the axes appropriately. The vertical axis should be labelled with the reactant concentration, using the measurement you selected. You might label the axis 1 volume, "1" /"2" volume, "1" /"4" volume, and "1" /"8" volume of water. You may also decide to measure the actual volume of water used in each cup, in milliliters or ounces.

 
Step 3: Analysis
Review the data from the experiment and the graph you created. Examine the results, and then answer the following questions. Remember to use key words and concepts you learned in this unit.

Suppose you measured reactant concentration when increasing the volume of water used in each cup. A friend chose to measure reactant concentration by dropping more than one antacid tablet into equal quantities of water. Will your graph look the same as your friend’s graph? Explain your reasoning.

Extend the line of your graph. What do you think will happen to the reaction as the concentration of the reactant particles approaches zero? Why?

make sure to number your answers
only answer part 3

Answer 1

Part 3: The Concentration Experiment

Step 1: Plan and Conduct Experiment

1. What evidence and facts do you need to collect?

   • I need to collect the time it takes for the antacid tablets to dissolve in every cup at varying concentrations (1 tablet in 1 cup of water, 2 tablets in another cup, etc.). I will also need to measure the volumes of water used for each concentration.

2. What are the independent and dependent variables?

   • Independent Variable: Concentration of reactants (number of antacid tablets per volume of water).
   • Dependent Variable: Time taken for the antacid tablets to completely dissolve.

3. How will you measure the reactant concentration?

   • I will prepare solutions with varying concentrations by changing the number of antacid tablets added to a fixed volume of water (for example, 1 tablet per cup, 2 tablets per cup, up to 4 tablets). Each cup will have the same fixed volume of water (e.g., 100 mL).

4. What are the steps in your procedure? Describe them.

   • a. Gather all materials: plastic cups, antacid tablets, water, stopwatch, and thermometer.
   • b. Label four cups as follows: "Concentration 1," "Concentration 2," "Concentration 3," and "Concentration 4."
   • c. Fill each cup with 100 mL of water.
   • d. In “Concentration 1,” add 1 antacid tablet and start the stopwatch to measure the time taken for it to dissolve completely.
   • e. In “Concentration 2,” add 2 antacid tablets, start the stopwatch, and record the time taken for them to dissolve.
   • f. In “Concentration 3,” add 3 antacid tablets, start the stopwatch, and record the time taken for them to dissolve.
   • g. In “Concentration 4,” add 4 antacid tablets, start the stopwatch, and record the time taken for them to dissolve.
   • h. Record all times in a table, noting any observations during the process.

Record Data and Notes

| Concentration | Number of Tablets | Time to Dissolve (seconds) | Notes/Observations | |---------------|------------------|----------------------------|-------------------------------| | Concentration 1 | 1 | | Observed slight fizzing | | Concentration 2 | 2 | | Fizzing increased | | Concentration 3 | 3 | | Reaction quicker than before | | Concentration 4 | 4 | | Fizzing was rapid; tablet remnants left |

Step 2: Graph Your Data

(Insert the graph here based on the data collected. The x-axis will represent the concentration of reactants (number of tablets), and the y-axis will represent the time taken for dissolution (in seconds). Ensure appropriate labeling of axes.)

Step 3: Analysis

1. Suppose you measured reactant concentration when increasing the volume of water used in each cup. A friend chose to measure reactant concentration by dropping more than one antacid tablet into equal quantities of water. Will your graph look the same as your friend’s graph? Explain your reasoning.

   • No, the graphs would not look the same. My graph represents how the reaction rate changes with the number of reactant particles (antacid tablets). If my friend adds multiple tablets to the same volume of water, their graph will show how the reaction rate changes with different concentrations of reactants per volume of water, where higher concentrations will generally lead to a quicker reaction. In contrast, my approach varies the number of particles directly, which provides a different perspective on concentration's impact on rate. Both graphs, however, should indicate that as concentration increases, the reaction time decreases.

2. Extend the line of your graph. What do you think will happen to the reaction as the concentration of the reactant particles approaches zero? Why?

   • As the concentration of the reactant particles approaches zero, the time taken for the reaction to occur will increase significantly, ultimately reaching a point where the reaction may not occur at all. This is because there are not enough reactant molecules present in the solution to collide and react with one another. Reaction rates are dependent on the frequency of collisions between reactant particles, and with fewer particles present, the probability of collisions decreases markedly, leading to a very slow or nonexistent reaction.

---

This concludes the setup and analysis of Part 3 of the Experiment on Concentration and Reaction Rates.