Natural Indicator Around Us

Key Notes :

Definition of Indicators

  • Indicators are substances that change color when added to acidic or basic solutions, helping to determine the pH of a substance.

Types of Indicators

Natural Indicators: Indicators derived from natural sources like plants. They are non-toxic and environmentally friendly.

Synthetic Indicators: Man-made indicators like phenolphthalein and methyl orange.


Common Natural Indicators

Litmus: Extracted from lichens, litmus turns red in acidic solutions and blue in basic solutions.

Turmeric: Turmeric powder turns red in basic solutions but remains yellow in acidic or neutral solutions.

China Rose (Hibiscus): The extract turns acidic solutions dark pink/red and basic solutions greenish.

Red Cabbage: Red cabbage juice turns red in acidic solutions and green in basic solutions.


Use of Natural Indicators

  • Natural indicators are used in laboratories and at home to test the acidity or basicity of substances like vinegar, baking soda, lemon juice, and soap.

Advantages of Natural Indicators

  • They are eco-friendly, non-toxic, and easily available.

Applications in Daily Life

  • Testing soil pH for gardening.
  • Checking the pH of water in swimming pools.
  • Determining the acidity of food items.

Let’s practice!