Reaction Rates, Catalysis, and Pasteurization

Interactive, scaffolded model

Overview and Learning Objectives

This activity introduces key ideas of chemistry, including reaction rates, bond strength, activation energy, catalysis, and equilibrium.

Students will be able to:

• describe and manipulate models to discover how reaction rates, energy, bond strength, catalysis, and equilibrium are related;
• manipulate reaction rates by changing temperature and concentration;
• demonstrate their understanding by creating an endothermic reaction that releases a lot of heat energy, one that requires a catalyst, and one that reaches equilibrium between reactants and products.

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Assessment

Download a pre- and post-assessment from:

http://www.concord.org/~barbara/workbench_web/pdf/assess_chem_rxn.3.pdf

Rubric

http://www.concord.org/~barbara/workbench_web/pdf/assess_chem_rxn_rubric.2.pdf

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Classroom Practice

This activity covers many key ideas in chemistry; these are also critical to understanding cellular functions that involve chemical reactions.

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Central Concepts

Key Concept:

Bonds are made and broken when atoms and molecules collide with sufficient energy and orientation. Energy is released when bonds are made; energy is required to break a bond.

Additional Related Concepts

Concept Map Available

Molecular Biology

• Enzyme

Physics/Chemistry

• Bonds
• Breaking bonds
• Catalysis
• Chemical reaction
• Range of reactions
• Reaction rate
• Reversability of reaction

Systems

• Equilibrium

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Textbook References

• Biology (Prentice-Hall) New York Edition - Chapter Eight: Photosynthesis
• Biology (Prentice-Hall) New York Edition - Chapter Two - The Chemistry of Life
• BSCS Blue (8th Edition) - Chapter 1: The Chemistry of Life
• BSCS Blue (8th Edition) - Chapter 5: Cell Respiration: Releasing Chemical Energy
• Cell Biology (Pollard and Earnshaw) Saunders 2002 - Chapter Three: Basic Biophysical Concepts
• Web of Life - Chapter 2: Chemical Basis of Life

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Benchmarks and Standards

AAAS

• THE PHYSICAL SETTING: THE STRUCTURE OF MATTER - The rate of reactions among atoms and molecules depends on how often they encounter one another, which is affected by the concentration, pressure, and temperature of the reacting materials (Full Text of Standard)
  
  

NSES

• Life Science: The Cell - 2 Most cell functions involve chemical reactions (Full Text of Standard)
  
  
• Physical-Science: Chemical Reactions - 1 Chemical reactions occur all around us, for example in health care, cooking, cosmetics, and automobiles (Full Text of Standard)
  
  
• Physical-Science: Chemical Reactions - 2 Chemical reactions may release or consume energy (Full Text of Standard)
  
  
• Physical-Science: Chemical Reactions - 4 Chemical reactions can take place in time periods ranging (Full Text of Standard)
  
  
• Physical-Science: Chemical Reactions - Catalysts, such as metal surfaces, accelerate chemical reactions (Full Text of Standard)
  
  

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Extensions and Connections

Students might like to go on to activities such as:

Polymerization (Activity)

http://molo.concord.org/database/activities/282.html

or Explosion (Demo)

http://molo.concord.org/database/activities/62.html

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Activity Credits

Created by CC Project: Molecular Logic using Molecular Workbench

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Requirements

• Java 1.5+ - Java 1.5+ is available for Windows, Linux, and Mac OS X 10.4 and greater. If you are using Mac OS X 10.3, you can download MW Version 1.3 and explore within it instead.

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