Question

Write scientific reasons.

Lemon or tamarind is used for cleaning copper vessels turned greenish.

Answer 1

Copper vessels turned greenish due to the formation of the copper carbonate layer. The citric acid present in the lemon or tamarind neutralizes the basic copper carbonate and dissolves the layer. That is why tarnished copper vessels are cleaned with lemon or tamarind juice to give the surface of the copper vessel its characteristic luster.