If you collect silver coins and copper coins you may have seen that after some days a black coating forms on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the chemical name of the black and green coatings.

You are given the following materials (i) Marble chips (ii) dilute hydrochloric acid (iii) Zinc granules Identify the type of reaction when marble chips and zinc granules are added separately to acid taken in two test tubes.

Updated 1/12/2026

When carbon dioxide is passed through lime water, it turns milky, why?

Updated 1/12/2026

What do you understand by precipitation reaction? Explain with suitable examples.

Updated 1/12/2026

What is a balanced chemical equation?

Updated 1/12/2026