Acids and Bases

A WebQuest for (10-12) (Chemistry)

by Almeda C. Luster

Introduction | Task | Resources | Process | Evaluation | Conclusion

Introduction

This project will cover properties of acids and bases, calculations of acidic and basic solutions, and activities on acids and bases. Strengths of acids and bases will be determined through activities using titrations, pH scales and pH meters, and other types of indicators. Theories such as Arrenius and Bronsted acids and bases will be researched. Finally, the student will construct a pH scale using household products to determine acidic and basic content.

• The learner will create and construct a pH scale of various household products to show the levels of acidic and basic content
• The learner will distinguish acidic and basic solutions.
• The learner will bring household items to classify as acids or bases in a lab activity
• The learner will work practice problems on calculating pH and pOH
• The learner will give a group summary of how pH is relevant to everyday experiences

  ---

Resources

 The student will find the following links to be helpful while studying how to distinguish acids and bases, how to categorize acids and bases, and when researching properties of acids and bases:

Chemical Kitchen

Determining Acids and Bases

Background Information on Naming Acids, Bases, and Salts

The student will find the following links to be helpful while performing pH calculations:

Calculations of pH and pOH

Calculating pH

The student will find the following links to be helpful while researching activities on acids and bases:

Cabbage Juice Indicator Activity

Properties of Acids and Bases Activity

Titrations

The student will also use the texts Addison Wesley Chemistry and Heath Chemistry as resources.

 To accomplish the given task, the learners will use the provided resources to create and construct a pH scale of various household products to show the levels of acid and base content in each product.

• First you will collect different household products from various rooms in your home such as kitchen items, bathroom items, bedroom items, pantry items, garage items, and even items from your automobiles.
• Once you have collected different products, a test must be done on each product by using pH meters, pH paper, or any other test that has been taught. Students may work in groups of four.
• After testing for the different ranges of pH, each student must construct a visual display of at least 10 different products showing the names of each household product, and a systematic range of pH. The visual display can be done on poster boards, graph paper, construction paper, or any means of choice of paper. A key must be provided to denote the format of your display so that anyone can follow through, read, and understand your findings.
• Finally, you will give a brief oral presentation to illustrate and share your findings.

  ---

Evaluation

 The criteria for evaluating your performance will be based on the following checklist items:

1. Each group must test at least ten products for the pH content
2. Each student must construct a visual display of ten products and the pH of each in a neat format
3. A key must be provided to denote the display format
4. All students will receive an individual grade on his own display
5. Each group must give a brief oral presentation of findings
6. Grades will be based on neatness, originality, completion of the task, and how well the student orally presents his findings.

  Proceed to the rubric to assess student performance.

 Upon completion of this activity on constructing a pH scale of different household products, you will have learned how to test for acid and base contents in products. Also you will have accomplished how to arrange the pH of each product and construct a visual display in a systematic style that shows at least ten products tested.

To further extend your thinking, consider the following questions:

• How do manufacturers decide on what the pH of shampoos should be?
• What is the relevance of pH in the manufacturing of deodorants for men as opposed to women?
• In what other areas could you use your results from this activity?