What are the characteristics of chemical reactions?
Answers
Characteristics of chemical reactions
* The conversion of reactants into products in a chemical reaction is often accompanied by some features which can be observed easily.
*The important characteristics of chemical reactions are:
1. Evolution of gas.
2. Formation of a precipitate.
3. Change in colour.
4. Change in temperature.
5. Change in state.
1. Evolution of gas
Some chemical reactions are characterized by the evolution of gas. The chemical reaction between zinc and dilute sulphuric acid is characterized by the evolution of hydrogen gas.
* Take some zinc granuals in a conical flask.
* Add dilute sulphuric acid over zinc granuals.
*We will see the bubbles of hydrogen gas being formed around the zinc granuals.
*If we touch the conical flask with our hand, we will find that it is somewhat hot. So, a change in temperature also occur in this chemical reaction.
2. Formation of precipitate
A precipitate is a solid product which separates out from the solution during a chemical reaction.
The chemical reaction between potassium iodide and lead nitrate is categorised by the formation of a yellow precipitate of lead iodide.
* Take some lead nitrate solution in test tube.
* Add potassium iodide to the solution.
* A yellow precipitate of lead iodide is formed at once.
* A change in colour also takes place in this chemical reaction.
Answer:
Heya ☺
Characteristics :
➡ evolution of a gas
➡ formation of a precipitate
➡ change in colour
➡ change in temperature
➡ change in state