Question

One of the signs of a chemical reaction taking place is:

Answer 1

• formation of precipitate
• change in state
• change in colour
• evolution of a gas
• change in temperature

Step-by-step explanation:

these signs show that the chemical reaction has taken place.

Answer 2

Precipitates indication release of gas

Or just vapor-again indictaing release of gas

Change in melting/boiling point, change in pH

Change in temperature