This document defines and describes different types of chemical reactions. It states that a chemical reaction involves the transformation of one or more substances into products with different properties. Chemical reactions are represented by equations showing reactants and products. The main types of reactions discussed are combination, decomposition, displacement, and double displacement reactions. The document also discusses endothermic and exothermic reactions, neutralization reactions between acids and bases, and the classification of oxides as basic, acidic, amphoteric, or neutral based on how they react.

1. Chemical Reactions
Any chemical change in matter
which involves transformation
into one or more substances with
entirely different properties is
called a chemical reaction.
A chemical reaction is
represented by a
chemical equation.
Substance(s)
taking part –
Reactant(s)
New substance(s)
obtained –
Product(s)
❑ Combination Reaction (or Synthesis)
❑ Decomposition Reaction
❑ Displacement Reaction
❑ Double Displacement Reaction
E.g.:-
Fe(s) + S(s) → FeS(s)
NH3(g) + HCl(g) → NH4Cl(g)
A + B + .. → C + D + ..
Types of Chemical Reactions
Two substances combine to
form a single substance
Combination Reaction
(or Synthesis)
A + B → AB
E.g.:-
2Hgo(s) → 2Hg + O2
2AgCl → 2Ag + Cl2
Decomposition reaction
One substance breaks
down into two or
more simple ones
E.g.:-
Zn + CuSO4(aq) → ZnSO4(aq) + Cu
2Na + 2H2O → 2NaOH + H2
AB + C → CB + A
C displaces
A from its
molecule.
Displacement Reaction
Double Displacement
Reaction
AB + CD → CB + AD
E.g.:-
AgNO3(aq) + HCl → AgCl + HNO3
CuO + HNO3→ Cu(NO3)2 + H2O
Two compounds in their
aqueous state displace
ions or radicals.

2. A chemical reaction in which a base or
alkali reacts with an acid to produce
salt and water.
▪ Exothermic Reaction
▪ Endothermic Reaction
A Chemical reaction in
which heat is released.
A Chemical reaction in
which heat is absorbed.
Oxides
Metallic
Oxides
Non-
Metallic
Oxides
Amphoteric Oxides: Oxides
which are of dual nature and
react with both bases and acids
to produce salt and water. Eg.
Zinc, Lead, Aluminium Oxide.
Non-Metallic
Oxides
Neutralization Reaction
Acid + Base/Alkali → Salt + Water
Metal Reactivity Series
Types of reactions based on energy exchange
Basic Oxides : Most of the
metallic-oxides are basic in
nature and react with acids
to produce salt and water.
Eg. Sodium, Calcium,
Magnesium Oxide.
➢ Formed on heating metals
➢ Some are formed on heating
metallic, cabonates, nitrates, etc.
Metallic Oxides
Acidic Oxides : Most of the
non-metallic oxides are acidic
in nature and react with bases
to produce salt and water. Eg.
Carbon, Sulphur dioxide,
Phosphorus Pentoxide.
➢ Formed on heating non-metals
Neutral Oxides : Oxides which are
neutral in nature and do not
change the colour of indicators. Eg.
Water, nitric, nitrous oxide.