Classifying Substances

The Acidic Environment‎ > 1. Indicators‎ > ‎

Solve problems by applying information about the colour changes of indicators to classify some household substances as acidic, neutral or basic

Substances can be classified as acidic, neutral or basic by following this simple procedure:

  • If necessary, add water to the substance being classified.
  • Place samples of the substance in four test tubes, and add one of the following indicators to each:
    • Litmus.
    • Phenolphthalein.
    • Methyl orange.
    • Bromothymol blue.
  • Using the colour changes observed and the indicator ranges, classify the substance as acidic, basic or neutral.