Question

give two example where a chemical reaction is accompanied by a change in color of the reactants&products on completion of the reaction​

Answer 1

I can give one example. That is copper.

When copper reacts with the elements (oxygen, water and carbon dioxide), it turns from its element color of reddish-brown to green. This chemical reaction is hydrated copper carbonate, and a famous example of it is the Statue of Liberty.

Answer 2

Answer:

example of your question is in the precense of sodaNAOHand WATER H2O potassium permangateKMNO4 which is purple in colour reacts with sugar to form pot6