Ncert science chemical reaction and reaction

May 07, 2019

Ncert science chemical reaction and reaction

CHEMICAL REACTION

&

EQUATION

CHEMICAL REACTION

A process in which new substance are found with new properties is called chemical reaction

for example :- when magnessium is born in the air . It formed megnessium oxide oxide having new properties and new substance therfore it is chemical reaction.

CHARACTERISTICS OF CHEMICAL REACTION:-

*change in temperature

*change in color

*evolution of gasses

* change in state

A+C --------------> C

*A+B =REACTANT

*C = PRODUCT

--------------> DIRECTION OF REACTION

CHEMICAL EQUATION

The representation of the chemical reaction with the help of symbols and formulas of the compound include in that reach on is called chemical equation.

for example:- magnessium + oxygen = magnessium oxide

mg + o2 = mgo

UNBALANCED CHIMICAL EQUATION

If in a chemical equation number of the atom of reactant are not equal to the number of the atom of the product then this reaction is known as unbalanced chemical equation.

For example :-mg +o2 =mgo

balanced chemical equation

if in a reaction number of the atom of the reactant is equal to the number of the atom of the product then the equation is known as balanced chemical equation

for example :- 2mg + o2 = 2mgo

Types of chemical reaction

*combination reaction

*decomposition reaction

* displacement reaction

*double displacement reaction

*oxidation reaction /reduction reaction /redox reaction

COMBINATION REACTION

If in a reaction two reactant combined together to form a new compound is known as combination reaction

for example :- c + o2 ---------->co2

NOTE :- most of the combination reaction are exothermic in nature

exothermic reaction :-

a reaction which produce heat and release it due to the force of reaction is known as exothermic reaction.

Example :- cao +h20 -------------------->cacoh2 + heat

quick lime slaked water

DECOMPOSITION REACTION

A reaction in which single reactant rate down into two or more compound or by obsorbing heat is called decomposition reaction .

for example :- caco3 ---------> cao +co2

Electro lightning decomposition

when the decomposition of a compound take place with the help of electricity then the decomposition is known as electro lightning decompotion

DISPLACEMENT REACTION

When in the reaction more reactant element desplaces the less reactant element from there salt solution is known as displacement reaction .

LP------------------------------------------------------------- HIGEST REACTIVE

CLL

AG ------------------------------------------------------------LESS REACTIVE

DOUBLE DISPLACEMENT REACTION

If in a reaction when two reactant react with each other by exchanging there ions then the reaction is known as double displacement reaction.

OXIDATION / REDUCTION/ REDOX REACTION

OXIDATION:-

The addition of some other electro negative electrone in a compound or removable of other positive electrone is also known as oxidation .

reduction

Addition of the hydrogen and the removable of the other positive electron is known as reduction .

Redox reaction

A reaction in which oxidation and the reduction take place that is called redox reaction.