complete overview of chemical reactions along with their types. it contains chemical reaction and equation types of chemical reaction (5 types) corrosion rancidity

1. class 10

2. TOPICS
 INTRODUCTION
 CHEMICAL REACTION
 CHEMICAL EQUATION
 TYPES OF CHEMICAL REACTION
 CORROSION
 RANCIDITY

3. what is a chemical
reactions? Chemical reaction, a process in which one or more
substances, the reactants, are converted to one or more
different substances, the products. Substances are
either chemical elements or compounds.
 Example of chemical reaction in everyday life
I. photosynthesis
II. combustion
III. Respiration
IV. Rust
V. Digestion
VI. Cooking

4. Identification of
chemical reaction
 It can be determined by 4 factors
i. change in state
ii. change in color
iii. change in gas
iv. change in temp
According to the law of conservation of
mass matter can neither be created
nor be destroyed, & it is discovered by
ANTOINE LAVOISER

5. What is chemical
equation?
 Symbolic representation of chemical
reaction.
 It can be written in two form word and
formula.
Word form:
magnesium + oxygen magnesium oxide
Formula form:
mg+02 mgo

6. How to generate chemical
equations?
 Reactants are written in LHS
 Product are written in RHS
 It is used to show direction of reaction:
 “+” is placed between different reactant and
products.
mg+o2 mgo
(reactant) (product)

7. What are the type of
chemical equations?
 Balanced chemical equation
It is an equation for a chemical reaction in
which the number of atoms for each element in
the reaction and the total charge are the same for
both the reactants and the products.
 Unbalanced chemical equation
It is an equation where the no of atoms for
elements anf their total charge are not equal in
both side.

8. How to balance a chemical
equation?
 First count the atoms of each element
in the reactants and the products.
 Use coefficients to place them in front
of the compounds as needed.
 3fe+4h2o fe3o4+4h2
Note: It should not alter formula of
compound
it should not alter elements. Eg:
h2o4 ,(h2o)4

9. What are the type of
chemical reactions?
 Combustion reaction
 Decomposition reaction
 Displacement reaction
 Double-displacement reaction
 Oxidation-reduction reaction
 It involves the breaking &making of bond
between atom & production of new
substance.

10. Combination reaction
 A reaction in which single product is
formed from 2 or more reactant.
 Cao +H2O(l) –Ca(OH)2(aq)+heat
 Burning of coal:C(s)+O2(g)-CO2(aq)
 Formation of water: H(g) +O2(g)-H2O(l)
 Burning of natural gas:CH4(g)+O2(g)-
CO2(g)+H2O(l)

11. Decomposition reaction
 The reaction in which single reactant break down
to form simpler product
 CaCo3 Cao(s)+Co2(g);(in cement)
 Thermal decomposition-carried in presence of
heat.
 2Agcl(s) 2Ag(s)+cl2(g)
(sunlight) (grey)
used in white and black photography.

12. What are the types of
decomposition reaction?
 There are 3 types:
 Thermal decomposition or thermolysis
 Electrolytic decomposition or electrolysis
 Photodecomposition or photolysis

13. ELECTROLYTIC
DECOMPOSITION
 It results when an electric current passes through
an aqueous solution.
 Uses of electrolytic decomposition:
 electrolysis of water is the decomposition of
water into oxygen and hydrogen gas due to an
electric current
 When we pass electricity in a solution of NaCl and
water NaCl is broken in ions. current being passed
through the water.

14. Thermal decomposition
 The break down of a substance into other simpler
substances under the effect of heat is
called thermal decomposition.
 The reaction is usually endothermic as heat is
required to break chemical bonds in the compound
undergoing decomposition.

15. PHOTODECOMPOSITION
Photodecomposition reaction is one in which the
compound breaks when a light of suitable wavelength
falls over it .
For example :
when Silver Chloride is exposed to sunlight , it
decomposes to form silver metal and chlorine gas

16. DISPLACEMENT REACTION
 A displacement reaction is a type
of reaction in which part of one reactant is
replaced by another reactant.
 A displacement reaction is also known as
a replacement reaction or a metathesis
reaction.
 There are two types of displacement
reaction.

17. What are type of
displacement reaction?
 Single displacement reaction
These are the reactions where one reactant replaces
part of the other:
AB + C → AC + B
eg: Fe + CuSO4 → FeSO4 + Cu
 Double displacement reaction
These are reactions where the cations and anions in
the reactants switch partners to form products:
AB + CD → AD + c
eg: AgNO3 + NaCl → AgCl + NaNO3

18. REDOX REACTION
 A redox (or oxidation-reduction) reaction is a type
of chemical reaction that involves a transfer of
electrons between two specie
 It involves two terms:
oxidation- gain of oxygen or loss of hydrogen
Reduction- gain of hydrogen or loss of oxygen
Cuo+H2 Cu+H2O
 There are two types of agent:
oxidizing agent
Reducing agent

19. REDOX
 Oxidizing agent:
It is the substance which give oxygen or gain
hydrogen.
It can also be termed as it reduces itself and
oxidized other.
 Reducing agent:
It is the substance which gain oxygen or give
hydrogen.
It can also be termed as it oxidizes itself and
reduced other.

20. What is corrosion?
 Corrosion is a process through which metals in
manufactured states return to their natural oxidation
states.
 This process is a reduction-oxidation reaction in which
the metal is being oxidized by its surroundings.
 RUST-It is red or orange coating form on the surface of
iron.
The chemical mechanism of corrosion is “OXIDATION”.

21. What is rancidity?
 It is generally known as oxidation of fats.
 It is caused by a biochemical reaction between
fats and oxygen
 In this process the long-chain fatty acids are
degraded and short-chain compounds are
formed.
 Cause:
oxidation in food items.

22. What are the effects of
rancidity?
 accelerated aging,
 tissue damage
 development of cancer diabetes
 Alzheimer's disease.
 reduces the nutritional
value of the food product.