Introduction

Many common household solutions contain acids and bases. Acid-base indicators, such as litmus and red cabbage juice, turn different colors in acidic and basic solutions. They can, therefore, be used to show if a solution is acidic or basic. An acid turns blue litmus paper red, and a base turns red litmus paper blue. The acidity of a solution can be expressed using the pH scale. Acidic solutions have pH values less than 7, basic solutions have pH values greater than 7, and neutral solutions have pH equal to 7.

Objectives

In this experiment, you will

  • Test household solutions with litmus paper.
  • Test household solutions using red-cabbage juice indicator.
  • Determine the pH values of household solutions.
  • Classify household substances as acids or bases.
  • Determine the different red cabbage juice indicator colors over the entire pH range.
  • Use red cabbage juice indicator to test other household substances.