investigating burning ethanol. steps in investigation 1.initial prediction and explanation...
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Steps in Investigation 1.Initial prediction and explanation 2.Observations: Measurements of changes in mass and CO 2 3.Learning about 5 practices for describing chemical changes 4.Constructing an argument from evidence that combines claims, evidence, and reasoningTRANSCRIPT
Investigating Burning Ethanol
Steps in Investigation
1. Initial prediction and explanation2. Observations: Measurements of changes in
mass and CO2
3. Learning about 5 practices for describing chemical changes
4. Constructing an argument from evidence that combines claims, evidence, and reasoning
Steps in Investigation
1. Initial prediction and explanation2. Observations: Measurements of changes in
mass and CO2
3. Learning about 5 practices for describing chemical changes
4. Constructing an argument from evidence that combines claims, evidence, and reasoning
In your own words….
• Explain what happens when ethanol burns. Try to include in your explanation:– All the materials (solids, liquids, and gases) that are
changed when ethanol burns. These are called reactants.
– All the materials that result from ethanol burning. These are called products.
– Changes in energy: what happens to the chemical energy in the ethanol.
• Predict changes that we will be able to measure
Ethanol burning
Ethanol
Beforeburning
Afterburning
Predictions for change in mass
When ethanol burns, what happens to it and the things it needs to burn?
Use the Process Tool to Show Your Prediction and Explanation
Steps in Investigation
1. Initial prediction and explanation
2. Observations: Measurements of changes in mass and CO2
3. Learning about 5 practices for describing chemical changes
4. Constructing an argument from evidence that combines claims, evidence, and reasoning
A Question about BTB
BTB (bromothymol blue) is an indicator that changes color when there is lots of carbon dioxide in the air. How could you figure out what color it changes?
Use the tables in your worksheet to record
• Mass of ethanol before and after for BTB experiment
• Color changes in BTB• Mass of ethanol before and after for soda lime
experiment• Mass of soda lime before and after• Other observations you made• Possible problems with accurate measurement
and how to make the measurements as accurate as possible.
Steps in Investigation
1. Initial prediction and explanation2. Observations: Measurements of changes in
mass and CO2
3. Learning about 5 practices for describing chemical changes
4. Constructing an argument from evidence that combines claims, evidence, and reasoning
Five Practices for Finding Chemical Change in Life and Lifestyles
Questions What to Notice Principle or Rule to FollowHave you identified all the materials that are changing (the reactants and products)?
Organic materials: Foods, fuels, and living and dead organismsGases: carbon dioxide, oxygen, and water vapor
Conservation of matter: Chemical changes do not create or destroy matter; the amount of matter is the same in reactants and products
Have you kept track of all the materials, even the gases?Can you show that no mass was lost or gained in the reaction?
All states of matter: solids, liquids, and gases all have massNot energy: heat, light, work, and chemical energy do not have mass
Conservation of mass: Chemical changes do not change mass; the mass of the reactants equals the mass of the products
Can you show that all the atoms present in the reactants are present in the products? Can you identify which materials are composed of organic molecules?
Atoms: carbon (C), oxygen (O), hydrogen (H), other atoms such as nitrogen (N), and phosphorous (P)Organic molecules that have C-C or C-H bondsInorganic molecules, including CO2, H2O, and O2
Conservation of atoms: Chemical changes rearrange atoms into new molecules, but they do not create or destroy atoms
Can you show that energy was not gained or lost in the reaction?
Chemical energy stored in the C-C and C-H bonds of organic moleculesOther forms of energy, including light, work (motion), and heat
Conservation of energy: Chemical changes transform energy without changing the total amount of energy, BUT some energy is always changed into heat that cannot be reused
Can you identify where the event fits in large-scale systems, including ecosystems and human energy systems?
Movement of carbon from pools of organic materials to inorganic materials and back againFlow of energy from sunlight to chemical energy to work and heat
Matter cycles: carbon and other elements cycle between organic and inorganic materialsEnergy flows: sunlight is converted to chemical energy, then to work and heat
How did you use three practices to explain which materials will burn?
• The materials practice: • Identifying organic and inorganic materials• The subsytems practice:• Identifying C-C and C-H bonds in molecules• The energy practice• Identifying materials with more chemical
energy
Steps in Investigation
1. Initial prediction and explanation2. Observations: Measurements of changes in
mass and CO2
3. Learning about 5 practices for describing chemical changes
4. Constructing an argument from evidence that combines claims, evidence, and reasoning
Claim, evidence, and reasoning
• Claim: What is your revised explanation of what happens when alcohol burns, including reactants, products, and energy transformations?
• Evidence: What observations and measurements support your claim?
• Reasoning: How does the evidence support your claim?
Ethanol burning
Ethanol
Beforeburning
Afterburning
Predictions for change in mass
When ethanol burns, what happens to it and the things it needs to burn?
Use the Process Tool to Show Your New Explanation
Does your explanation conserve matter?
Practice What to Notice Principle or Rule to Follow
The Materials Practice: Identify the materials that are changing: Reactants and products
Organic materials: Foods, fuels, and living and dead organismsGases: carbon dioxide, oxygen, and water vapor
Conservation of matter: Chemical changes do not create or destroy matter; the amount of matter is the same in reactants and products
The Mass/gases Practice: Find the masses of reactants and products
All states of matter: solids, liquids, and gases all have massNot energy: heat, light, work, and chemical energy do not have mass
Conservation of mass: Chemical changes do not change mass; the mass of the reactants equals the mass of the products
The Subsystems Practice: Find out what is happening in subsystems at the microscopic scale (cells) and the atomic-molecular scale (atoms and molecules)
Atoms: carbon (C), oxygen (O), hydrogen (H), other atoms such as nitrogen (N), and phosphorous (P)Organic molecules that have C-C or C-H bondsInorganic molecules, including CO2, H2O, and O2
Conservation of atoms: Chemical changes rearrange atoms into new molecules, but they do not create or destroy atoms
The Energy Practice: Find out how energy is transformed in the event
Chemical energy stored in the C-C and C-H bonds of organic moleculesOther forms of energy, including light, work (motion), and heat
Conservation of energy: Chemical changes transform energy without changing the total amount of energy, BUT some energy is always changed into heat that cannot be reused
The Large Scale Practice: Find out where the event fits in large-scale systems, including ecosystems and human energy systems
Movement of carbon from pools of organic materials to inorganic materials and back againFlow of energy from sunlight to chemical energy to work and heat
Matter cycles: carbon and other elements cycle between organic and inorganic materialsEnergy flows: sunlight is converted to chemical energy, then to work and heat
Does your explanation conserve mass?
Practice What to Notice Principle or Rule to FollowThe Materials Practice: Identify the materials that are changing: Reactants and products
Organic materials: Foods, fuels, and living and dead organismsGases: carbon dioxide, oxygen, and water vapor
Conservation of matter: Chemical changes do not create or destroy matter; the amount of matter is the same in reactants and products
The Mass/gases Practice: Find the masses of reactants and products
All states of matter: solids, liquids, and gases all have massNot energy: heat, light, work, and chemical energy do not have mass
Conservation of mass: Chemical changes do not change mass; the mass of the reactants equals the mass of the products
The Subsystems Practice: Find out what is happening in subsystems at the microscopic scale (cells) and the atomic-molecular scale (atoms and molecules)
Atoms: carbon (C), oxygen (O), hydrogen (H), other atoms such as nitrogen (N), and phosphorous (P)Organic molecules that have C-C or C-H bondsInorganic molecules, including CO2, H2O, and O2
Conservation of atoms: Chemical changes rearrange atoms into new molecules, but they do not create or destroy atoms
The Energy Practice: Find out how energy is transformed in the event
Chemical energy stored in the C-C and C-H bonds of organic moleculesOther forms of energy, including light, work (motion), and heat
Conservation of energy: Chemical changes transform energy without changing the total amount of energy, BUT some energy is always changed into heat that cannot be reused
The Large Scale Practice: Find out where the event fits in large-scale systems, including ecosystems and human energy systems
Movement of carbon from pools of organic materials to inorganic materials and back againFlow of energy from sunlight to chemical energy to work and heat
Matter cycles: carbon and other elements cycle between organic and inorganic materialsEnergy flows: sunlight is converted to chemical energy, then to work and heat
Does your explanation conserve atoms?
Practice What to Notice Principle or Rule to FollowThe Materials Practice: Identify the materials that are changing: Reactants and products
Organic materials: Foods, fuels, and living and dead organismsGases: carbon dioxide, oxygen, and water vapor
Conservation of matter: Chemical changes do not create or destroy matter; the amount of matter is the same in reactants and products
The Mass/gases Practice: Find the masses of reactants and products
All states of matter: solids, liquids, and gases all have massNot energy: heat, light, work, and chemical energy do not have mass
Conservation of mass: Chemical changes do not change mass; the mass of the reactants equals the mass of the products
The Subsystems Practice: Find out what is happening in subsystems at the microscopic scale (cells) and the atomic-molecular scale (atoms and molecules)
Atoms: carbon (C), oxygen (O), hydrogen (H), other atoms such as nitrogen (N), and phosphorous (P)Organic molecules that have C-C or C-H bondsInorganic molecules, including CO2, H2O, and O2
Conservation of atoms: Chemical changes rearrange atoms into new molecules, but they do not create or destroy atoms
The Energy Practice: Find out how energy is transformed in the event
Chemical energy stored in the C-C and C-H bonds of organic moleculesOther forms of energy, including light, work (motion), and heat
Conservation of energy: Chemical changes transform energy without changing the total amount of energy, BUT some energy is always changed into heat that cannot be reused
The Large Scale Practice: Find out where the event fits in large-scale systems, including ecosystems and human energy systems
Movement of carbon from pools of organic materials to inorganic materials and back againFlow of energy from sunlight to chemical energy to work and heat
Matter cycles: carbon and other elements cycle between organic and inorganic materialsEnergy flows: sunlight is converted to chemical energy, then to work and heat
Does your explanation conserve energy?
Practice What to Notice Principle or Rule to FollowThe Materials Practice: Identify the materials that are changing: Reactants and products
Organic materials: Foods, fuels, and living and dead organismsGases: carbon dioxide, oxygen, and water vapor
Conservation of matter: Chemical changes do not create or destroy matter; the amount of matter is the same in reactants and products
The Mass/gases Practice: Find the masses of reactants and products
All states of matter: solids, liquids, and gases all have massNot energy: heat, light, work, and chemical energy do not have mass
Conservation of mass: Chemical changes do not change mass; the mass of the reactants equals the mass of the products
The Subsystems Practice: Find out what is happening in subsystems at the microscopic scale (cells) and the atomic-molecular scale (atoms and molecules)
Atoms: carbon (C), oxygen (O), hydrogen (H), other atoms such as nitrogen (N), and phosphorous (P)Organic molecules that have C-C or C-H bondsInorganic molecules, including CO2, H2O, and O2
Conservation of atoms: Chemical changes rearrange atoms into new molecules, but they do not create or destroy atoms
The Energy Practice: Find out how energy is transformed in the event
Chemical energy stored in the C-C and C-H bonds of organic moleculesOther forms of energy, including light, work (motion), and heat
Conservation of energy: Chemical changes transform energy without changing the total amount of energy, BUT some energy is always changed into heat that cannot be reused
The Large Scale Practice: Find out where the event fits in large-scale systems, including ecosystems and human energy systems
Movement of carbon from pools of organic materials to inorganic materials and back againFlow of energy from sunlight to chemical energy to work and heat
Matter cycles: carbon and other elements cycle between organic and inorganic materialsEnergy flows: sunlight is converted to chemical energy, then to work and heat
Evidence of CO2 in air from burning4 minutes
8 minutes
10 minutes, with control