- Take a few zinc granules in a conical flask or a test tube.
- Add dilute hydrochloric acid or sulphuric acid to this
- (Fig. 1.2).
- CAUTION: Handle the acid with care.
- Do you observe anything happening around the zinc granules?
- Touch the conical flask or test tube. Is there any change in its temperature?
Any of the following observations helps us to determine whether a chemical reaction has taken place –
- change in state
- change in colour
- evolution of a gas
- change in temperature.