There are 3 things that tell us if a chemical reaction has taken place. What are they? We could see that a _______________ is given off. We could see that there is an energy _________________.

Asked on by ishazainab

1 Answer | Add Yours

gsenviro's profile pic

gsenviro | College Teacher | (Level 1) Educator Emeritus

Posted on

Actually, there are several indicators of a chemical reaction.

  • We could see that a smell or odor is given off. Think about the burning of waste material.
  • We could see that there is an energy change. The energy may be consumed (endothermic reactions require energy supplied generally through heating) or generated (exothermic reactions give off heat). Think about the burning of coal or wood. This is also exhibited through a change in the temperature of the solution.
  • We could see the formation of new compounds, which could be solid, liquid or gaseous in nature. Think about precipitation of solids.
  • A color change may take place. Think about rusting, how color is seen on fresh metal surfaces.
  • A change in composition may take place.
  • A change in volume may take place.

We’ve answered 319,654 questions. We can answer yours, too.

Ask a question