Question

56. Write any two observations in an activity which may suggest that a chemical reaction has taken place. Give an example in support of your answer.

Answer 1

Answer:

Hey friend here is your answer :)

Step-by-step explanation:

Any two of these observations will suggest chemical reaction has taken place.

(i) Change in state.

(ii)Change in colour.

(iii) Evolution of gas.

(iv)Change in temperature.

For example, lead nitrate is white crystalline solid which on heating gives yellowish brown solid (lead monoxide). A brown gas and a colourless gas is also evolved. It shows chemical reaction has taken place.