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What Happens During a Chemical Reaction

Here you will know what happens during a chemical reaction. In this article, we will discuss different types of chemical reactions and their complete explanation.

Chemical Reaction:-  A change in which the chemical composition of the substance is changed is called a chemical reaction.

A chemical change brings a change in chemical properties that's why it is called a chemical reaction. 

What Happens During a Chemical Reaction

What are the characteristics of chemical reactions class 10

1. Formation of a new substance

2. Change in temperature

3. Evolution of gases

4. Formation of a precipitate (insoluble substance)

5. Change in physical state

6. Change in colour of the substance(s)

1. Formation of a  new substance

 During a chemical reaction one or more  new substances are produced that are called products

         Reactant →Product

          A+ B →  AB

         `2Mg + O_2 \rightarrow 2MgO`

in the above reaction, Magnesium oxide is a product.

2. Change in temperature

During a chemical reaction, a change in temperature can be observed.

The temperature may increase or decrease. Temperature increases in exothermic reactions and temperature decreases in endothermic reactions.

  `N_2+ O_2 +180.5kJ\rightarrow 2NO`(Endothermic reaction)

In this reaction, 180.5kJ of energy is absorbed.

  `C + O_2\rightarrow CO_2  + 395kJ`(Exothermic reaction)

In this reaction, 395 kJ of energy is released.

3. Evolution of gases

 In some chemical reactions, one or more gases are produced.

`Pb(NO_3)_2 \rightarrow PbO(s)   + NO_{2(g)}   + O_{2(g)}`

Two gases nitrogen dioxide and oxygen are produced.

 `Zn + H_2SO_4 \rightarrow  ZnSO_4 + H_{2(g)}`

Hydrogen gas is produced.

4. Formation of a precipitate

In some chemical reactions, precipitate an insoluble solid is formed.

`Na_2SO_4  + BaCl_2  \rightarrow BaSO_4(s)↓ + NaCl(aq)`

Barium sulphate is an insoluble solid substance formed during this reaction.

5. Change in physical state

In some chemical reactions, products are in different physical states.

`2H_2O_{(l)} \rightarrow  2H_{2(g)}  + O_{2(g)}`

In this reaction, water is in a liquid state and products hydrogen and oxygen are in a gaseous state.

6. Change in colour

During some chemical reactions, colour gets changed when products are formed.

`Fe + CuSO_4  \rightarrow FeSO_4  + Cu`

         (blue)                     (faded green)

Copper sulphate is blue and product Ferrous sulphate is faded green in colour.

These are the main characteristics of a chemical reaction, These changes do not occur in all chemical reactions.

Today we will discuss different types of chemical reactions and know what happens during a particular reaction.

                -------------Topics -------------

1. What happens when magnesium ribbon is burnt?

2. What happens when Zinc reacts with sulphuric acid?

3. What happens when barium chloride reacts with sodium sulphate?

4. What happens when copper is heated in the air?

5. What happens when a potassium iodide solution is added to a solution of lead nitrate?

6. What happens when lead nitrate is heated?

7. What happens when silver chloride is exposed to sunlight?

8. What happens when iron nails are placed in copper sulphate?

9. What happens when silver nitrate reacts with sodium chloride?

10. What happens when quick lime is added to water?

11. What happens when limestone is heated?

12. Sodium hydroxide reacts with sulphuric acid

13. What happens to natural gas when it is burned?

14.  What happens when silver bromide is exposed to sunlight

15. What is rancidity?

16. What is corrosion?

17. What is rusting of iron?

18. What is a combination reaction?

19. What is decomposition reaction?

20. What is displacement reaction?

21. What is a precipitation reaction?

22. What is the oxidation reaction?

23. What is a reduction reaction?

24. What is a redox reaction?

25. What is the neutralization reaction?

26. Are neutralization reactions displacement reactions?

27. Are neutralization reactions exothermic reactions?

28. Electrolysis of water

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