Chem

In this section, you will learn: 

• Types of chemical reactions

• Types of pH indicators

• Types of experiments

Types of chemical reactions:

• Acid

  • Acid + Metal => Salt + Hydrogen

  • Acid + Carbonate => Carbon Dioxide + Water + Salt

  • Acid + Alkali => Salt + Water (Neutralisation reaction)

• Alkali

  • Alkali + Ammonium salt => Ammonia + Salt + Water

  • Alkali + Acid => Salt + Water (Neutralisation reaction)

Types of pH indicators

• Litmus paper

  • • Acids

      • Turns from blue to red

    • Alkali/ Base

      • Turns from red to blue

• Methyl Orange

  • • Acids 

      • pH 3.1 - 4.4

      • Below 3.1: Red

      • Between 3.1 - 4.4: Orange

      • Above 4.4: Yellow

• Phenolphthalein

  • • Alkali

      • pH 8.1 - 10.0

      • Below 8.1: Colourless

      • Between 8.1 - 10.0: Faint Pink

      • Above 10.0: Pink

• Universal Indicator

  • • Acid

      • Red, Orange, Yellow

    • Neutral

      • Green

    • Alkali/ Base

      • Turquoise, Blue, Purple

• Thymol blue

  • • Acid

      • Red

    • Neutral

      • Yellow

    • Alkali/ Basic

      • Blue

• Bromothymol blue

  • • Acid

      • Yellow

    • Neutral

      • Green

    • Alkaline

      • Blue