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Physical and Chemical Changes - Coggle Diagram
Physical and Chemical Changes
There are 2 types of Changes
Physical Changes
-In a Physical Change,a substance undergoes changes only in its physical properties such as-
Shape
Size
Color
State
Chemical Changes
-A Chemical Change occurs when 2 substances react chemically to form new substances with different chemical properties.
A chemical change is also known as a
Chemical reaction
Original Substances in the Reaction are known as
Reactants
The new Substances formed are known as
Products
.
Rusting Of Iron
- When Iron is Left exposed to moist air,it chemically reacts with oxygen and water in the air to form
a powdery red substance called Rust
Prevention Of Rusting
-If we coat the iron with zinc or chromium it is known as
Galvinisation
Formation of Precipitate and Changes in Energy
Formation Of Precipitate
-When 2 Chemicals in a solution form to react an insoluble product it settles down as a precipitate.
Changes In Energy
- There are 2 types of changes in Energy.
Exothermic Reactions
- In a reaction if heat is released it is known as an
exothermic reaction
.
Endothermic Reactions-
When a reaction takes place with an absorption of heat It is known as an
Endothermic reactions
Types Of Chemical Reactions
Combination Reactions
-In a reaction if a new substance is formed from its constituent elements it is known as a
Combination Reaction
Example- 2Mg + O2 ---> 2MgO
Decomposition Reaction
- In a reaction if a compound is broken into it's constituent elements it is known as a
Decomposition Reaction
Example- CuCO3 ---> CuO + CO2**
Single Displacement Reaction
-In this reaction If 1 element replaces the another 1 element it is known as a
Single Displacement Reactions
CuSO4+Fe--->FeSO4+Cu
Double Displacement Reaction-
*
In this Reaction 2 compounds react by exchanging their elements
thus the name
**
Double Displacement Reaction
*Example- AB + CD = AD + CB
Precipitation Reaction-
In this Reaction 2 compounds react in their aqueous state to form an insoluble product which appears in the form of a precipitate.
For.eg NaCl+AgNO3--->AgCl | +NaNO3
Neutralisation Reaction
-In this Reaction an acid and a base react together to form salt and water
.For eg. H2SO4+2NaOH--->Na2SO4+2H2O
Oxidation and Reduction Reaction**
-Oxidation is the loss of electrons during a reaction by a molecule,atom or ion. For eg.C+O2--->CO2
Reduction.-The opposite process is called Reduction** which occurs when there is a gain of electrons
.For eg. Cl2+H2--->2HCl