Class 7
Chapter 6 Class 7 - Physical and Chemical Changes
  • Burning of magnesium ribbon

Magnesium (Mg) + Oxygen (O 2 ) → Magnesium oxide (MgO) (burns with a bright light)


  • Adding Water to Magnesium Oxide 

Magnesium oxide (MgO) + Water (H 2 O) → Magnesium hydroxide [Mg(OH)2] (Magnesium Hydroxide is a base)

  • Adding vinegar to baking soda

Vinegar (Acetic acid) + Baking soda (Sodium hydrogencarbonate) → Carbon dioxide + other substances

  • Reaction of Copper sulphate with iron

Copper sulphate solution (blue) + Iron → Iron sulphate solution (green) + Copper (brown deposit)


  • Reaction of carbon dioxide with lime water

Carbon dioxide (CO 2 ) + Lime water [Ca(OH)2] → Calcium Carbonate (CaCO 3 ) + Water (H 2 O)

Reaction of Lime Water with Carbon Dioxide - Teachoo-01.jpg

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Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 13 years and a teacher from the past 17 years. He teaches Science, Economics, Accounting and English at Teachoo