LAB Reaction Rates
Objectives
• Evaluate the effect of concentration on therate of a chemical reaction. ν
• Examine the effect of temperature on the rateof a chemical reaction.
Background: Many people believe that you cannot perform chemicalreactions without expensive equipment or costly chemicals. But thisisn’t true; chemical reactions happen everywhere. All you need is afood store to find many substances that can produce excitingchemical reactions.
Preparation
Materials
water | vinegar solution |
baking soda | balloons (3) |
plastic 0.5-liter | test tube |
soft-drink bottles (3) | 150-mL beakers (2) |
marker | 500-mL beaker |
stopwatch, or clock | 100-mL graduated |
with second hand | cylinder |
tape | |
Safety Precautions
Procedure
1. Read the procedure and safety information,and complete the lab form.
2. Make data tables similar to those shown onthe next page.
3. Prepare a 50 percent vinegar solution bymixing 30 mL of vinegar with 30 mL of water. This is solutionA.
4. Prepare a 30 percent vinegar solution bymixing 30 mL of vinegar with 70 mL of water. This is solutionB.
5. Prepare a 10 percent vinegar solution bymixing 30 mL of vinegar with 270 mL of water. This is solutionC.
6. Pour the vinegar solutions into theirassociated 0.5-L plastic bottles labeled A, B, andC.
7. Mark a small test tube about 1–2 cm from itsbottom. Fill the test tube to the line with baking soda. Pour thebaking soda into one balloon.
8. Repeat step 7 with two more balloons. Besure the amount of baking soda in each balloon is the same.
9. Place the mouth of one balloon over themouth of one 0.5-L bottle. Do not let any of baking soda fall intothe vinegar solution.
10. Repeat step 9 with the other two balloonsand the remaining bottles.
Inquiry Lab
11. Lift each balloon to allow the baking sodato fall into each vinegar solution. Time how long it takes for thereaction to finish. Measure how much each balloon inflates. Recordyour observations in your Concentration data table.
12. Carefully remove the balloons from thebottles.
13. Rinse the plastic bottles with water.
14. Prepare a 30 percent vinegar solution bymixing
30 mL of vinegar with 70 mL of cold water.
15. Prepare two more similar solutions withroom-temperature water and hot water.
16. Place the three solutions in the three0.5-L plastic bottles.
17. Repeat steps 7 and 8 to refill the balloonswith baking soda.
18. Place the balloons back on the bottles,repeating steps 9 and 10.
19. Repeat step 11. Time how long it takes forthe reaction to finish.
20. Measure how much each balloon inflates.Record your observations in your Temperature data table.
Concentration Data Table (Ballon circumferrence)
Vinegar Concentration | Solution A (50%) | Solution B (30%) | Solution C (10%) |
Observations | 8.5 cm | 6.20cm | 4.00cm |
Temperature Data Table (Circumferrence of ballon)
Solution temperature | Cold Room Temperature | Room Temperature | Hot temperature |
Observations | 3.50 cm | 5.00 cm | 7.00 cm |
Analyze Your Data
1. Describe how increasing the concentration ofa solution affects the rate of a chemical reaction. (Concentrationincreases rate increases)
2. Summarize how temperature affects the rateof a chemical reaction.(Temperature increases rate increases)
3. Explain why the balloons become inflated.(Because of Co2)
Conclude and Apply
4. Infer why the vinegar solutions in steps 3,4, and 5 were different volumes. Why couldn’t the volumes be thesame?
5. Predict what factors might affect the amountof product that is produced. What factors affect the rate at whichproducts are produced?
