Indicators were identified with the observation that the colour of some flowers depends on soil composition
Students learn to:
- classify common substances as acidic, basic or neutral
- identify that indicators such as litmus, phenolphthalein, methyl orange and bromothymol blue can be used to determine the acidic or basic nature of a material over a range, and that the range is identified by change in indicator colour
- identify and describe some everyday uses of indicators including the testing of soil acidity/basicity
Students:
- perform a first-hand investigation to prepare and test a natural indicator
- identify data and choose resources to gather information about the colour changes of a range of indicators
- solve problems by applying information about the colour changes of indicators to classify some household substances as acidic, neutral or basic
Extract from Chemistry Stage 6 Syllabus (Amended October 2002). © 2009, Board of Studies NSW.