Experiment #1 Design and Build a Closed Reaction Chamber

EXPERIMENT #1 DESIGN AND BUILD A CLOSED REACTION CHAMBER Overview

The principle of conservation of mass states that matter is neither created nor destroyed in a chemical reaction. The mass of reactant atoms is always equal to the mass of product atoms. This project focuses on a simple chemical reaction, the combustion, or burning, or sucrose (table sugar). When heat is added to sucrose, hydrogen and oxygen atoms are converted to water vapor, leaving solid carbon behind.

How can you measure the mass of these products? For this and many other chemical reactions, it is difficult to gather evidence to support the law of conservation of mass. In this project, you will try to solve the problem of containing the reactants and products of a chemical reaction. By measuring the masses of reactants and products, you will also determine if mass is changed or remains the same after the chemical reaction.

Project Rules o Design a solution for the problem of containing reactants and products in the combustion of sucrose. You must use the materials your teacher provides or approves. Your design must be approved as well. o Using your design, build a closed reaction chamber. o Evaluate your chamber, test it for leaks, ad modify it as needed. o Carry out the combustion of sucrose in your completed reaction chamber. Observe, measure, and record the results of the experiment. o Interpret your data and the pooled class data to determine whether mass is conserved in the reaction. o Present your findings in a visual display and oral presentation. In your presentation, you should include a description of the chamber you designed and the design process, as well as your experimental results and conclusions.

Project Hints 1. As you begin to design your reaction chamber, complete Project Worksheet 1. It will guide you in designing and building an effective closed reaction chamber that is suitable for the sucrose combustion experiment. 2. At the beginning of the sucrose experiment, add a small amount of sucrose of known mass to the can through the open bottle top. Record the mass of the sugar in the space provided in the Student Data Table on Project Worksheet 2. 3. After adding the sucrose, cover the bottle top with a balloon, and then find the mass of the chamber plus sucrose Record this value in the space provided in the Student Data Table. 4. When you burn the sucrose in the chamber, make sure the flame is centered beneath the can. Otherwise, the adhesive between the can and the bottle may melt. Make sure the flame is not too high for the same reason. 5. Always use proper safety precautions when using a flame. Safety goggles and lab aprons should be worn at all times. 6. Heat the sucrose until it turns black. Use tongs to handle the heated can or let the can cool before handling. Measure the mass of the reaction chamber. Record the final mass in the Student Data Table on Worksheet 2. 7. Use the Class Data Table on Worksheet 2 to pool data from the entire class. Use a calculator to find the class average. Also calculate the amount by which your change in mass differs from the class average. Record the results of your calculation sin the spaces provided in the Student Data Table. 8. Use the data tables, or graphs made from the data tables, in your class presentation. Prepare for your presentation by writing note cards that summarize how you designed your closed reaction chamber and any problems you had to resolve; how you carried out the experiment and what the results were; and the conclusions you drew about conservation of mass based on your data and the pooled class data.

Project Timeline

Task Due Date 1. Complete Worksheet 1 and design chamber ______2. Build, test, and modify chamber ______3. Complete sucrose combustion experiment ______4. Complete Worksheet 2 and draw conclusions ______5. Make presentation to the class ______

CLOSED REACTION CHAMBER Worksheet 1

This worksheet will walk you through the steps involved in making one type of closed reaction chamber suitable for burning sucrose. The reaction chamber is shown below. Use the figure as a guide.

1. Obtain an empty metal food can. Also, obtain an empty plastic water or soda bottle with about the same diameter as the can. Wash the can and bottle, and remove all the labels.

2. Cut off the top third of the bottle with scissors. Slide the bottle over the open end of the can as in the figure. Fasten the bottle to the can in this position using glue or tape.

3. Test the seal between the can and bottle by blowing into the top of the bottle and listening for escaping air. Find and seal any leaks.

4. Before adding the balloon to the bottle, add the sugar for the sucrose combustion experiment. Make sure you use the scale to measure the mass of the sugar first. Don’t forget to record the mass in Student Data Table on Worksheet 2.

5. After adding the sugar, put the balloon over the mouth of the bottle. An inadequate seal between the balloon and mouth of the bottle may result in a leaky chamber and loss of mass. This can be avoided by placing a tight rubber band over the balloon around the neck of the bottle.

6. Measure with the scale and record on Worksheet 2 the mass of the chamber plus sugar.

7. Set up the heat source as shown in the figure, and obtain your teacher’s permission to carry out the experiment. DATA TABLES FOR CLOSED REACTION CHAMBER EXPERIMENT Worksheet 2

This worksheet consists of data tables to record your data and the data from the rest of the class. The tables also have spaces for you to record individual changes in mass, the class average change in mass, and how your data differ from the class average. Initial mass of chamber and ballon (empty)______Student Data Table Initial mass of Final mass of Mass of sugar Change in Data Source chamber with chamber with (g) mass (g) reactants (g) products (g)

Your data

Class average

Deviation from

class average

To assist you in figuring the class average, write the numbers below, as reported in class. Then average these numbers by adding the columns and dividing by the number of data reported.

Initial mass of Final mass of Mass of sugar chamber with chamber with Change in (g) reactants (g) products (g) mass (g)

Lab Group 1

Lab Group 2

Lab Group 3

Lab Group 4

Lab Group 5

Lab Group 6

Lab Group 7

Lab Group 8

Lab Group 9

Total Mass Number of Groups Average Presentation Outline

You only have 3 minutes, so make sure what you say is important. Read the below questions, discuss them as a lab group, and write your answers in the spaces. You need to practice presenting, so START PRACTICING as if you were in front of the class as soon as you have all your answers.

1. Talk about building your closed reaction chamber. What problems did you have? How did you solve them? What did you find to be the best way to make your chamber?

2. What did your personal data show? Was your data in alignment with the LAW OF CONSERVATION OF MATTER?

3. Talk about something you learned from this presentation.

4. What would you have done differently in your lab if given a second chance?