Webquest: Acids and Bases

Introduction:

By the time you are in grades 10, 11 or 12, you have been taught about acids and bases from early coursework.

The effectiveness of previous science instructions on acids and bases is sometimes questionable for people who have completed high school. This is evidenced recently in the pseudo science, sometimes reported in different news media when acids and bases are brought up, as well as the discussion by politicians on various laws and proposals when discussing causes and solutions for acid rain. It is assumed that most of the politicians have taken science courses in their schooling, including material on acids and bases, but the misconceptions still seem to persist. For information purposes, the chemistry classes have been asked to give an informational presentation to our legeslative representative when he/she come to the high school seeking feedback from their constituents.

The purpose of this web quest is to expose students to real world situations of acids and bases, along with how their lives are being affected by acids and bases. They will have the opportunity to summarize their knowledge in a presentation.

Acid and Base theory is presently addressed in the Massachusetts Curriculum Frameworks:

Define Arrhenius theory of acids and bases in terms of the presence of hydronium and hydroxide ions, and Bronsteds theory of acids and bases in terms of proton donor and acceptor, and relate their concentrations to the pH scale.
Compare and contrast the nature, behavior, concentration and strengths of acids and bases.
Identify a buffer and explain how it works.
Describe an acid-base titration. Identify when the equivalence point is reached and its significance.
Calculate the pH or pOH of aqueous solutions using the hydronium or hydroxide ion concentration.

The task:

Student are to explore the web quest finding information about how they are affected by acids and bases. At the conclusion of the quest, you ( or your group) are to put together a 5 minute presentation, with visual aids (for example, PowerPoint if you know how, or a display board). The specific role of each person must be defined. After the presentation, you will also be given a self evaluation form where each person has to state their role in the process and/or product. In addition to defining what an acid or a base is, your presentation should be in one of the following 4 areas:

1) Acids and bases in air pollution.

2) Acids and bases in water pollution (and effects of buffer systems)

3) Environmental effects of acids and bases,

4) Acids and bases in the human body.

The process:

This assignment is to use the sites on the webquest to define and bases.

After defining acids and bases, explore the four options from the task using the suggested resources listed. Students are to construct a presentation, crediting sources for reference material.

Resources:

chemteam

http://dbhs.wvusd.k12.ca.us/webdocs/Base/Base.html

This is a nice site for basic definitions of acids and bases.