US Environmental Protection Agency
Epa: Determining the P H of Common Substances
In this acid rain experiment the students will be "determining the pH of common substances." This is a great lesson plan for an experiment.
US Environmental Protection Agency
Epa: Making a Natural P H Indicator
At this site you will find a step by step process for making a natural pH indicator. One of the main materials you need to have on hand is a red cabbage.
US Environmental Protection Agency
Epa: Measuring P H Experiment
This is an activity that deals with acid rain. "This experiment will illustrate how to measure the approximate pH of chemicals in water using a pH indicator." It is easy to follow the comprehensive set of directions.