Acid Rain Simulation
Students will create samples of "acid rain" in the laboratory, using a pH Sensor to quantify the change in acidity of the "rain water".
PASPORT pH Sensor (PS-2102)
Lab Summary
In this experiment, you will create samples of "acid rain" in the laboratory, using the pH Sensor to quantify the change in acidity of the "rain water". You will also complete several simple laboratory tests to determine what effects acid rain has on common substances.
Before falling to Earth as precipitation, water vapor in the atmosphere normally reacts with carbon dioxide gas to form a weak acid, carbonic acid (H2CO3). As a result, the pH of rainwater is approximately 5.6, making typical rainwater slightly acidic. However, water vapor in the atmosphere will also react in a similar fashion with other gases, including sulfur dioxide (SO2), nitrogen dioxide (NO2), and nitrogen trioxide (NO3). These gases are pollutants that result from the burning of fossil fuels: for example, in car exhaust and factory emissions. These reactions will produce acids stronger than carbonic acid, including sulfuric acid (H2SO4), nitric acid (HNO3), and sulfurous acid (H2SO3). If the concentration of these acids in the atmosphere is high enough, the pH of rainwater can be lowered considerably. Rain with a pH lower than 5.6 is considered "acid rain" and can have significant environmental effects on natural ecosystems and on buildings, statues, and other structures.
Note: Although most people consider the term "acid rain" to be a modern term, the English chemist Robert Angus Smith first used the phrase in 1852, noticing the connection between London's air pollution and the acidity of its rainfall.
Published: May 2002
Downloads
- Acid Rain Simulation - PASPORT (71 KB, .zip)
Includes experiment setup, procedures and Datastudio file
- Acid Rain Simulation - ScienceWorkshop (71 KB, .zip)
Includes experiment setup, procedures and Datastudio file
Here's What You Need
U.S. Educator prices shown.
Probeware (PASPORT Systems)
Xplorer GLX (PS-2002) - $329
The Xplorer GLX is a data collection, graphing, and analysis tool designed for science students and educators.
PASPORT pH Sensor (PS-2102) - $79
The pH sensor has a wide measurement range of 0 to 14 pH and high resolution, 0.01 pH.
Probeware (ScienceWorkshop Systems)
750 Interface, USB (CI-7650) - $659
The 750 Interface allows students to measure force, temperature, pressure, angular velocity, acceleration, current, & magnetic field with a built-in function generator and oscilloscope mode.
pH Sensor (CI-6507A) - $95
The pH sensor allows measurement of acidity or alkalinity of a solution.
Other Materials
- 6 M hydrochloric acid (HCl) -- approximately 2 ml, enough to fill pipette
- Sodium sulfite (Na2SO3), solid crystals -- 1 gram
- Test tubes, 20 x 150 mm (4)
- Disposable plastic Beral-type pipettes (2)
- Zip-seal plastic bag, 1-pint size
- Plastic wash bottle containing distilled water
- Small (25-ml) graduated cylinder
- Small strip of magnesium ribbon, marble chips (calcium carbonate, CaCO3), and/or small pieces of fresh apple skin for testing the effects of "acid rain"