You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.


  • Green coating on copper is copper carbonate. It is formed by the reaction of copper with carbon dioxide , moisture and oxygen in the atmosphere.
  • Copper is a metal . Hence, it forms a basic oxide .
  • So, Copper oxide is basic in nature.
  • Lemon and tamarind juice are acidic in nature.
  • Lemon / tamarind juice reacts with the basic copper oxide to neutralise it, forming salt and water and thus cleaning them.
  1. Class 10
  2. Chapter 3 Class 10 - Metals and Non-Metals (Term 1)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo