This document was prepared by Mr. Deepak Kumar, an academic officer at the SCERT Divisional Office Jammu. It discusses various types of chemical reactions including combination, decomposition, displacement, double displacement, precipitation, exothermic, endothermic, oxidation, and reduction reactions. Examples of each type of reaction are provided. The document aims to help readers understand how chemical reactions occur and differentiate between reaction types.

1. Prepared by :
Mr. Deepak Kumar
M.Sc. (Chemistry), B.Ed.
Academic Officer, Department of Teacher Education
Academic Unit II
SCERT Divisional Office Jammu.
Mobile No.: 9906145868.
Email : deep.bhagat2382@gmail.com
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REACTION

2.  Milk is left at room temperature during summers.
 An iron tawa/pan/nail is left exposed to humid
atmosphere.
 Grapes get fermented.
 Food is cooked.
 Food gets digested in our body.
 We respire.
 Relief we get with a right medicine/injection.
 Inconvenience due to wrong medicine/injection.

3. “One of the main
aims of chemistry is to
understand how
Chemical Reactions
occur.”

4.  Combination
 Decomposition
 Displacement
 Double Displacement
 Precipitation
 Exothermic
 Endothermic
 Oxidation
 Reduction

5. Example:
CaO (s) + H2O (l) Ca(OH)2 (aq.) + Heat
Quick Lime Slaked Lime
C (s) + O2 (g) CO2 (g)
Coal
A Reaction in which a single product is formed from two or
more reactants. It is also called an Addition Reaction.
A B AB

6. Example:
CaCO3 (s) CaO (s) + CO2 (g)
Limestone Quick Lime
A B
A Reaction in which a single reactant breaks down to
give simpler products.
It is opposite of combination reaction. Energy (Heat,
Light or Electricity) is often required. It is also called
Analysis.
AB +

7. A Reaction in which one element displace/remove
another element from its salt solution.
Example:
Fe (s) + CuSO4 (aq) FeSO4 (aq) + Cu (s)
Zn(s) + H2SO4 (aq) ZnSO4 + H2
A B C
+
A B C +

9. Example:
2NH4Cl (aq) + Ba(OH)2(aq) BaCl2 (aq.) + 2NH4OH
White ppt
NOTE: Not all Double-Displacement Reactions result in Precipitation.
A Reaction in which there is an exchange of ions between the reactants.

10. Any Reaction that produces a precipitate (ppt).
Such Reactions produce Insoluble Salts.

11. Reaction in which Heat is given out along with the Product(s).
Example:
CaO (s) + H2O Ca(OH)2 (aq.) + Heat
Quick Lime Slaked Lime

12. Reactions in which Heat is absorbed.

13. “Hot and cold are Nature’s
two hands with which she
cheerfully works.”

14. • Addition/Gain of Oxygen
• Removal/Loss of Hydrogen
2Cu + O2 2CuO
(Black)

15. • Addition/Gain of Hydrogen
• Removal/Loss of Oxygen
CuO + H2 Cu + H2O

16. S. No. Reaction Gain Loss
1 Oxidation
O H
2 Reduction
H O

17. “Where there is a oxidation,
there is always reduction –
Chemistry is essentially a
study of redox systems.”

18. • Analyse and differentiate between various types
of chemical reactions.
• Express Chemical reaction through a chemical
equation.
• Provide examples of different types of chemical
reactions.
• Predict the products of a chemical reaction.
• Apply concepts learnt in everyday problem.

19. From: JKSCERT – Jammu.