Module 8

Module 8—Acid-Base Equilibrium

Module Summary

 

In Module 8 you considered the following question:

• How does the equilibrium of acids and bases affect environmental and biological systems?

You investigated the equilibrium of acids and bases. You learned to consider solutions containing acidic and basic solutes as chemical systems in which principles of equilibrium are involved. These principles include extent of reaction, equilibrium position, calculation of equilibrium constant, and determination of solution pH.

 

You also continued to apply your understanding of techniques to analyze equilibrium systems, including ICE tables. Throughout this module you considered environmental and biological systems and how the equilibrium of acids and bases is a part of each system’s function. This module has also provided you an opportunity to review your understanding of acids and bases developed in your previous chemistry courses and to bring together your understanding of equilibrium to broaden your base of knowledge in this area.

 

You also learned about buffers, and you learned how these systems demonstrate the principles of equilibrium you studied in Module 7. You examined the importance of buffers in soil and in living systems.

Concept Map or Graphic Organizer

 

As you worked through Module 8, you may have added information to a concept map or graphic organizer based on the module and lesson questions listed in the Module 8 Concept Organizer. Now is a good time to review the relationships in your concept map or graphic organizer and to try to answer the module and lesson questions.

 

A sample Module 8 concept map shows one set of possible links between the questions. Remember that this is one possible description only—there are many other correct possibilities. However, if your completed concept map or graphic organizer differs significantly from the sample, you may wish to contact your teacher or to compare your map or organizer with those of other students in your class. This will ensure that your interpretations of lesson materials and your descriptions are accurate.

 

Module Assessment

 

This Assessment will serve as your Module 8 Assessment and your Unit D Assessment.

 

In your study in this module you have used the Relative Strengths of Acids and Bases table. Copies of this table are located on pages 8 and 9 of the Chemistry Data Booklet and on page 829 of the textbook. How is this table designed? In this Assessment you will investigate the structure and listing of information on this table. This Assessment consists of three questions.

1. List, in a general way, the information that is provided on the Relative Strengths of Acids and Bases table.
   
   
2. Explain how the information on the Relative Strengths of Acids and Bases table was used to support your work in Unit D. Use examples to support your response.
   
   
3. Describe a series of experiments that can be used to confirm the structure and organization of the Relative Strengths of Acids and Bases table. Make sure you include the following information in your response:
    
   • a description of experiments you would undertake
     
     
   • a list of the substances to be tested
     
     
   • a description of the tests to be performed and the equipment required to complete these tests
     
     
   • a statement of the expected results from the experiments and tests described
     
     
   • an explanation of how the expected results would confirm the organization of the Relative Strengths of Acids and Bases table

Scoring Guide

 

Score	Scoring Description
4 Standard of Excellence	The response is well organized and addresses all the major points of the question using appropriate and clear communication strategies. An appropriate and practical series of experiments is described. Thorough and correct justifications, interpretations, and explanations are provided.
3	The response is organized and addresses most of the major points of the question using appropriate and well formed communication strategies. Appropriate and workable experiments are described. Justifications, interpretations, and explanations are correct.
2 Acceptable Standard	The response is generally organized and addresses most of the major points of the question using logical and reasonable communication strategies. Workable experiments are generally described. Justifications, interpretations, and explanations are correct.
1	The response is poorly organized and addresses few of the major points of the question. Poorly formed arguments and descriptions are used. A plausible experiment is suggested. Justifications, interpretations, and explanations are incorrect or absent from the response.
0	The response is not suitable for a 30-level course.

 

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