Question

How do you prepare the natural indicators. ​

Answer 1

Answer:

Perform a first-hand investigation to prepare and test a natural indicator

Dip the ends of two strips of filter paper into the indicator and allow to dry.

Using an eyedropper, apply a drop of strong acid to one strip and a drop of strong base to the other strip.

Record any changes in colour.

Answer 2

Answer:

• To prepare a natural indictor:
• Select a suitable coloured plant material, such as purple cabbage.
• Extract the colour from the plant material by either:
• Boiling it in water.
• Crushing it with water or alcohol using a mortar and pestle.
• Decant the solution from the solid.To test a natural indicator:
• Dip the ends of two strips of filter paper into the indicator and allow to dry.
• Using an eyedropper, apply a drop of strong acid to one strip and a drop of strong base to the other strip.
• Record any changes in colour.
• Add additional drops of acid and base to the strips until no further changes in colour are observed.
• If an indicator is prepared from purple cabbage, the following colours should be observed:
• Initial/Neutral colour: Purple
• Colour when exposed to strong acid: Pink, then Red
• Colour when exposed to strong base: Blue-Green, then Yellow