Is it an Acid or Alkali?
Chemistry: Edexcel IGCSE, topic 12.1.2
Determining if a Substance is an Acid or Alkali
There are many ways of determining whether a substance is an acid or an alkali. We can determine the pH directly, or we can use an indicator. Examples of indicators are:
Litmus paper
- Litmus paper is:
- Red in acid.
- Blue in alkali.
Methyl orange
- Methyl orange is:
- Red in acid.
- Yellow in alkali.
Phenolphthalein
- Phenolphthalein is:
- Colourless in acid.
- Pink in alkali.
Test yourself on Is it an Acid or Alkali?
Which of these are true of litmus paper?
Which of these is colourless in acid?