ACID AND BASE INDICATORS

 

INDICATORS 

Indicators are the special type of materials used to test weather the substance is acidic or basic. Normally indicators change their colour when added to the substance containing an acid or base. 

Eg:- litmus, turmeric, china rose petals

LITMUS 

Litmus are most commonly using natural indicator. It is extracted from lichens. Normally it has purple colour solution, but when added to acid it turns red and in base it turns blue. It is also available as strips available as red and blue litmus papers. Blue litmus paper turns red in acid and no change in base. Red litmus turns blue in base and no change in acid. In neutral solution red and blue litmus doesn’t shows any colour change.

TURMERIC 

Turmeric is yellow in colour. It doesn’t shows any colour change in acidic and neutral solutions (remains yellow), when turmeric is added to basic solution it turns to deep red.

CHINA ROSE

Solution made of china rose petals is red in colour (can be made using china rose petal leaves put in boiled water for few hours). It turns magenta in acidic solution, green in basic solution and remains red in neutral solution.