Question

How do we come to know that a chemical reaction has taken place?

September 7, 2024

Answer

The presence of any of the following changes helps us to determine that a chemical reaction has taken place.

(i) Formation of new substance(s)

(ii) Change in state

(iii) Change in colour

(iv) Change in temperature

(v) Formation of a precipitate

(vi) Evolution of a gas

For example, if on mixing two substances a gas is evolved, then we can say that a chemical reaction has taken place.

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