Featured in PASCO’s College Biology Instructor Guide

College Biology Instructor Guide


College Instructor edition with 26 experiments covering introductory and general biology topics.

Air Pollution & Acid Rain

Lab Summary

Use a water quality sensor to measure the effects of CO2, SO2, and NO2 on the pH of water.


In this activity, students investigate chemical reactions that are important in the formation of acid rain to better understand the relationship between certain types of anthropogenic (manmade) emissions and problems arising from acid rain. During this investigation, students:

  • Determine the effect of different anthropogenic gases on the pH of water.
  • Explore the effects of changes in the pH of water on the environment.
  • Describe the effect of changes in the pH of water on living things.


Students will gain experience conducting the following procedures:

  • Learning the chemical reactions involved in generating three types of gases, carbon dioxide (CO2), sulfur dioxide (SO2), and nitrogen dioxide (NO2), that are common anthropogenic emissions.
  • Measuring the effect of CO2, SO2, and NO2 on the pH of water using a pH sensor.
  • Using radish plants exposed to acidic water as a model of the effects of acid rain on living things.

Sensors / Equipment Used:

PASPORT Water Quality Sensor


Measures temperature, conductivity, pH/ISE/ORP and dissolved oxygen. It is specifically designed for convenience in conducting water quality lab experiments. For use with PASPORT Interfaces.

Materials Used:

1 M HCl solution - 15 mL
1-hole rubber stopper for flask
Beaker, 40-mL
Electronic Balance - 1 per class
Erlenmeyer flask, 50-mL
Flexible Teflon tubing to fit glass tubing - 20 cm
Glass tubing for rubber stopper
Graduated cylinder, 10-mL
Graduated disposable pipet
Labeling marker
Latex or polypropylene gloves
Masking tape
Planting pots, 2 inch - 3
Radish seeds - 15
Sodium bicarbonate(NaHCO3) - 5 g
Sodium bisulfite(NaHSO3) - 5 g
Sodium nitrite (NaNO2) - 5 g
Vinegar - 400 mL
Wash bottle containing distilled or deionized water

The Associated Bundle:

College Biology Bundle


A complete probeware bundle designed for PASCO's College Biology curriculum

Interface Required

This experiment may require software and an interface for data collection.