Featured in PASCO’s Biology through Inquiry Teacher Guide

Biology through Inquiry Teacher Guide


Features 25 inquiry based labs covering the fundamental concepts of cell biology, ecology and physiology.

Water and pH

Lab Summary

Use pH and conductivity sensors to analyze the differences in how water pH changes when “acid rain” is added.


Students analyze the differences in how water pH changes when “acid rain” is added.

Analyze water from different sources for pH and conductivity.

  • Determine that water with more dissolved solids, for instance from a pond, lake, river, well, or swimming pool, is relatively resistant to changes in pH, after adding a small amount of acid.
  • Identify why mountain water sources and ecosystems are more susceptible to damage by acid rain or other forms of acidic or basic pollution than are water sources and ecosystems located at lower elevations in valleys.


Students gain experience conducting the following procedures:

  • Students measure the pH and conductivity of water from various sources and analyze the effect of “acid rain” on each of them.

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:

Beaker, 250-mL (4)
Distilled water - 250 mL
Graduated cylinder, 100-mL 
Labels (6)
Marking pen 
Small container (for diluted vinegar solution)
Stirring rod 
Water sample, 250 mL (3)
White vinegar - 250 mL

The Associated Bundle:

Biology Standard Sensor Bundle


The Biology Standard Sensor Bundle includes a photosynthesis tank and the sensors required to perform 19 of the 24 Lab Activities in the Biology through Inquiry manual.

Interface Required

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