Introduction

Organisms are often very sensitive to the effect of acids and bases in their environment. They need to maintain a stable internal pH in order to survive—even in the event of environmental changes. Many naturally occurring biological, geological, and man-made chemicals are capable of stabilizing the environment’s pH due to their buffering ability. This allows organisms to better survive in diverse environments found throughout the earth. Using a pH sensor, each lab group will measure the effect of an acid and a base in water. Each group will then test the effect of an acid and a base on a biological and/or non-biological material assigned to them. All groups will share their data at the end of class.

Objectives

  • Add an acid to a material and note the extent that it resists changes in pH.
  • Add a base to a material and note the extent that it resists changes in pH.
  • Work with classmates to compare the ability of different materials to resist pH changes.