Chem Connections


What Happens to Acid Rain?

Acid Rain Image


hat happens to acid rain?

Classroom or laboratory: both
Number of one hour class periods: 12 plus three additional computer activities
Number of 3-4 hour laboratory periods: 4 (some experiments require time between set-up and analysis)

George C. Lisensky, Department of Chemistry, Beloit College, Beloit, WI 53511

Description

What happens to the oxides of sulfur and nitrogen produced during combustion? Where do they go and how do they affect the environment? This module is intended for use in an analytical chemistry course and asks students to consider the consequences when soil equilibria are stressed. What chemical species are important in the soil system charge balance? How are changes in pH, solubility, and ion-exchange interlinked with ion distributions and concentrations? How does the chemical system shift and the ecosystem respond? Instead of many simple problems where individual equilibria are studied separately, students are asked to question and investigate facets of a more complex problem through laboratory measurements of model and natural systems, supplemented by case studies.

Tool Kit:
Chemical Principles:
* Equilibria (Le Chatelier's Principle, gas equilibria, solubility, acids and bases, buffers, redox reactions, distribution equilibria)
* Laboratory Procedures (analytical methods, instrumental techniques)

Thinking Like a Scientist:
* Experimental Design (sampling, controls/calibration)
* Data Analysis (statistical analysis of data, analysis of the impact of the results on society)
* Critical Thinking/Problem Solving (reasoning, order of magnitude estimates)
* Systems Modeling (simulations, computation of complex interactions)
* Communicate Results (writing, speaking)

Audience: sophomore analytical chemistry

Prerequisites: ions, moles, acids/bases, Lewis structures, oxidation states, and equilibria

Interdisciplinary components: Aspects of this geochemistry module belong to geology, biology, and chemistry. "What happens to acid rain?" is an international question and studies/data from outside the US will be extensively used.

Materials to be developed

Multimedia Materials

  • Collection of graphs/data for class analysis/discussion/investigation (leaders guide)
  • Collection of equilibria software/tools

Standard Materials

  • Introduction to multiple types of equilibria (student guide)
  • Laboratory directions for structured inquiry and collaborative learning
  • Annotated bibliography


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Last modified: 10/18/00 at 11:26 AM