Unit 7 Catalysts Pre Lab Answers
Lab 7: Catalysts
Introduction
Pre-Lab Questions
1. What is a catalyst? An enzyme is a biological catalyst that speeds up chemical reactions in the body.
2. If you continue to add more catalyst will the speed of a reaction always continue to increase? Explain your answer. It will continue to speed up the reaction until there is more catalyst than the limiting reactant.
3. In this lab you will produce oxygen and water from hydrogen peroxide (H2O2). Write a balanced reaction equation for this reaction. 2H2O2(l)------>2H2O(l)+O2(g)
4. What causes the bubbles to form in this reaction? The production of oxygen (O2)
5. The exhaust gas from car engines pass through catalytic converters that contain very small amounts of solid platinum, palladium,
and rhodium catalysts. Are these metals homogeneous or heterogeneous catalysts? Heterogeneous catalysts
Lab 7: Catalysts
Experiment: Reactions with Catalysts
Table 1: Catalyst Comparison Observations
Type of Catalyst
Initial Observations
Final Observations
Carrot
Bubbles started forming on the carrot instantly
The carrot is still covered in bubbles
Tomato
Nothing happened immediately
The hydrogen peroxide is breaking down the tomato
Soil
Bubbles begin forming right away
The dirt is bubbling like crazy
Yeast
Many bubbles formed right away bubbling all the way up the test tube.
The reaction finished almost immediately and is not doing anything anymore.
Table 2: Catalyst Quantity Observations
Amount of Yeast
Observations
1 mL
Bubbled to about 1/3 of the test tube
5 mL
Bubbled to about 2/3 of the test tube
10 mL
Bubbled to about 2/3 of the test tube
Title
Catalysts
Purpose
To better understand catalyst and understand what they do in your body.
Hypothesis
That the yeast will definitely break down the hydrogen peroxide and that the dirt will break it down as well. The carrot and tomato won’t do anything. Also, the 1mL of yeast to the hydrogen peroxide will break down but not as much as fast. The 5ml will do it fast and a lot. The 10ml I think will be similar to the 5ml because there will be more enzyme than the limiting reactant.
Data
Carrot: Bubbles started forming on the carrot instantly
Tomato: Nothing happened immediately
Dirt: Bubbles begin forming right away
Yeast: Many bubbles formed right away bubbling all the way up the test tube.
1mL: Bubbled to about 1/3 of the test tube
5mL: Bubbled to about 2/3 of the test tube
10mL: Bubbled to about 2/3 of the test tube
Observations
The yeast was the best and fastest reaction of the first test tubes.
The 10mL of yeast went no faster than the 5 because the limiting reactant was fully saturated with 5mL.
Calculations
There were no calculations in this lab.
Conclusion
That the yeast breaks down hydrogen peroxide the best. And that for 1mL of hydrogen peroxide anything over 5mL of yeast solution is not needed.
Post Lab Questions
1. Classify each catalyst you used as homogeneous or heterogeneous.
Homogeneous catalysts: Yeast solution
Heterogeneous catalysts: Carrot, tomato, dirt
2. Which catalyst made the reaction go the fastest? Is it a homogeneous or heterogeneous catalyst? homogeneous
3. Which catalyst would be the easiest to remove from the water that was formed? Is it a homogeneous or heterogeneous catalyst? heterogeneous
4. Which amount of yeast solution you tested would be the best to use? Explain your answer. 5mL because it is as fast as it can get and fully saturates all of the limiting reactant.
Introduction
Pre-Lab Questions
1. What is a catalyst? An enzyme is a biological catalyst that speeds up chemical reactions in the body.
2. If you continue to add more catalyst will the speed of a reaction always continue to increase? Explain your answer. It will continue to speed up the reaction until there is more catalyst than the limiting reactant.
3. In this lab you will produce oxygen and water from hydrogen peroxide (H2O2). Write a balanced reaction equation for this reaction. 2H2O2(l)------>2H2O(l)+O2(g)
4. What causes the bubbles to form in this reaction? The production of oxygen (O2)
5. The exhaust gas from car engines pass through catalytic converters that contain very small amounts of solid platinum, palladium,
and rhodium catalysts. Are these metals homogeneous or heterogeneous catalysts? Heterogeneous catalysts
Lab 7: Catalysts
Experiment: Reactions with Catalysts
Table 1: Catalyst Comparison Observations
Type of Catalyst
Initial Observations
Final Observations
Carrot
Bubbles started forming on the carrot instantly
The carrot is still covered in bubbles
Tomato
Nothing happened immediately
The hydrogen peroxide is breaking down the tomato
Soil
Bubbles begin forming right away
The dirt is bubbling like crazy
Yeast
Many bubbles formed right away bubbling all the way up the test tube.
The reaction finished almost immediately and is not doing anything anymore.
Table 2: Catalyst Quantity Observations
Amount of Yeast
Observations
1 mL
Bubbled to about 1/3 of the test tube
5 mL
Bubbled to about 2/3 of the test tube
10 mL
Bubbled to about 2/3 of the test tube
Title
Catalysts
Purpose
To better understand catalyst and understand what they do in your body.
Hypothesis
That the yeast will definitely break down the hydrogen peroxide and that the dirt will break it down as well. The carrot and tomato won’t do anything. Also, the 1mL of yeast to the hydrogen peroxide will break down but not as much as fast. The 5ml will do it fast and a lot. The 10ml I think will be similar to the 5ml because there will be more enzyme than the limiting reactant.
Data
Carrot: Bubbles started forming on the carrot instantly
Tomato: Nothing happened immediately
Dirt: Bubbles begin forming right away
Yeast: Many bubbles formed right away bubbling all the way up the test tube.
1mL: Bubbled to about 1/3 of the test tube
5mL: Bubbled to about 2/3 of the test tube
10mL: Bubbled to about 2/3 of the test tube
Observations
The yeast was the best and fastest reaction of the first test tubes.
The 10mL of yeast went no faster than the 5 because the limiting reactant was fully saturated with 5mL.
Calculations
There were no calculations in this lab.
Conclusion
That the yeast breaks down hydrogen peroxide the best. And that for 1mL of hydrogen peroxide anything over 5mL of yeast solution is not needed.
Post Lab Questions
1. Classify each catalyst you used as homogeneous or heterogeneous.
Homogeneous catalysts: Yeast solution
Heterogeneous catalysts: Carrot, tomato, dirt
2. Which catalyst made the reaction go the fastest? Is it a homogeneous or heterogeneous catalyst? homogeneous
3. Which catalyst would be the easiest to remove from the water that was formed? Is it a homogeneous or heterogeneous catalyst? heterogeneous
4. Which amount of yeast solution you tested would be the best to use? Explain your answer. 5mL because it is as fast as it can get and fully saturates all of the limiting reactant.