Speed and Acceleration Lab



Factors Affecting Chemical Reaction Rates Lab

Name ______________________________________

Date ______________________ Block ____________

********************************************************************************************

Background: In this lab you will explore two factors which can affect reaction rates, concentration of reactants and temperature of reactants. The reaction you will perform can be summarized as follows:

- Iodate ions (IO3-1) react with bisulfite ions (HSO3-1) forming I2 molecules

- The I2 quickly reacts with more busulfite to form I-1 ions

- As all the bisulfite ions are consumed I2 remains in solutions and forms a complex molecule with starch. This complex is deep blue in color.

Question and Hypothesis:

How does temperature of reactants affect the rate of a chemical reaction?

Experiment 1: Temperature vs. Reaction Rate

Variables:

Independent:

Dependent:

Constants:

- Test tube size for reaction to occur (surface area)

- Amount (10 mL) of each solution (concentration of reactants) in each test tube

Materials:

- 6 test tubes, same size

- 30 mL of solution A, iodate ions

- 30 mL of solution B, bisulfite ions

- 3 250 mL OR LARGER beakers

- Ice

- Water

- Test tube clamps

- Stopwatches

- Hot plate

- Thermometer

Procedure:

1. DO NOT pour anything back into the original supply bottle.

2. Be sure to completely clean out your test tubes between each trial.

3. Set up 3 250 mL OR LARGER beakers: one with ice water, one with room temperature water, and one with water on a hot plate set to the lowest setting.

4. Pour 10 mL of solution A into three test tubes (10 mL in each test tube) and place on in each beaker (cold, room temperature, and hot). Do not let the liquid spill out of the test tube.

5. Repeat step 4 for solution B.

6. Let these test tubes come to thermal equilibrium (reach the temperature of the water they are in throughout the entire solution). While you wait, complete the next experiment Concentration of Reactants vs. Reaction Rate

7. When thermal equilibrium is reached, combine the A and B test tubes from each beaker and measure the time it takes to complete the reaction—for the solution to be deep blue. Record the time in data table 1. You will time three different reactions:

▪ Cold A+B

▪ Room temperature A+B

▪ Warmed A+B

Data:

Table 1: Affect of temperature on chemical reaction rate measured in seconds

|Temperature °C |Trial 1 (seconds) |Trial 2 (seconds) |AVERAGE (seconds) |

|Cold _____°C | | | |

|Room Temperature _____°C | | | |

|Warm _____°C | | | |

Analysis

Title:

[pic]

Background: In this lab you will explore two factors which can affect reaction rates, concentration of reactants and temperature of reactants. The reaction you will perform can be summarized as follows:

- Iodate ions (IO3-1) react with bisulfite ions (HSO3-1) forming I2 molecules

- The I2 quickly reacts with more busulfite to form I-1 ions

- As all the bisulfite ions are consumed I2 remains in solutions and forms a complex molecule with starch. This complex is deep blue in color.

Question and Hypothesis:

How does concentration of reactants affect the rate of a chemical reaction?

Experiment 2: Concentration of Reactants vs. Reaction Rate

Variables:

Independent:

Dependent:

Constants:

- Test tube size for reaction to occur (surface area)

- Temperature

Materials:

- 6 test tubes, same size

- 17.5 mL of solution A, iodate ions

- 30 mL of solution B, bisulfite ions

- Water

- Stopwatches

- Thermometer

Procedure:

1. DO NOT pour anything back into the original supply bottle.

2. Be sure to completely clean out your test tubes between each trial.

3. Pour 10 mL of solution A into one test tube.

4. Pour 10 mL of solution B into one test tube.

5. Begin timing the reaction as you combine test tubes A and B—carefully mix them back and forth a couple of times. Do not spill the solutions.

6. Record the time it takes for the reaction to stop in data table 2—for the solution to be deep blue.

7. Pour 5 mL of solution A and 5 mL of water into one test tube.

8. Pour 10 mL of solution B into one test tube.

9. Begin timing the reaction as you combine test tubes A and B—carefully mix them back and forth a couple of times. Do not spill the solutions.

10. Record the time it takes for the reaction to stop in data table 2—for the solution to be deep blue..

11. Pour 2.5 mL of solution A and 7.5 mL of water into one test tube.

12. Pour 10 mL of solution B into one test tube.

13. Begin timing the reaction as you combine test tubes A and B—carefully mix them back and forth a couple of times. Do not spill the solutions.

14. Record the time it takes for the reaction to stop in data table 2—for the solution to be deep blue..

Data:

Table 2: Affect of reactant concentration on chemical reaction rate measured in seconds

|Concentration (solution A / water) |Trial 1 (seconds) |Trial 2 (seconds) |AVERAGE (seconds) |

|(mL) | | | |

|10/0 | | | |

|5/5 | | | |

|2.5/7.5 | | | |

Analysis

Title:

[pic]

IN ADDITION TO YOUR CONCLUSION (conclusions include: 1) your results, 2) if your results support your hypothesis, and 3) what you learned; BE SURE TO INCLUDE THE ANSWERS TO THESE Conclusion Questions:

1. If two separate atoms are floating around in a container, when might they form a bond? What do they have to do?

2. List two ways you could increase the concentration of a gaseous reactant.

3. List one way to increase the concentration of a dissolved substance.

4. Describe the effect of temperature and concentration on the speed of the reaction. The reaction is complete when the solution turns blue.

5. Why does increasing the concentration of a reactant make a reaction go faster?

6. Why did an increase in temperature cause an increase in the reaction rate?

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download