CHAPTER No. 1ST
CHEMICAL REACTION AND
CHAPTER NAME EQUATION
(CHEMISTRY)
, CHEMICAL REACTIONS AND EQUATIONS CLASS X SCIENCE
Chemical Change: The changes in which chemical property of a substance is change is called chemical
change.
Example: 1. Formation of curd. 2. Digestion of food.
3. Burning of fuel like petrol, diesel, wood etc. 4. Rusting of iron.
4. Cooking food 6. Grapes get fermented
Chemical Reaction:-When two or more substances are react together to form one or more new
substances, is called chemical reaction.
Effects of chemical reaction:
1. Always new substances are formed
2. Gas may be released.
3. Heat may be release or absorb.
4. Colour of solution may be change.
5. Metal may be deposited on electrode.
Representation of chemical reaction : Chemical reaction can be represented by two ways :
1. Word Equation : The representation of any chemical reaction in the form of word is called word
equation.
Example : Hydrogen gas combines with nitrogen to form ammonia.
Nitrogen + Hydrogen Ammonia
2. Chemical Equation :- The symbolic representation of any chemical reaction, is called chemical
equation.
Example :- 1. Burning of Coal (C) : C + O2 CO2
2. Burning of Methane : CH4 + O2 CO2 + H2O + Energy
Chemical Reaction has two part :-
1. Reactant 2. Product
1. Reactants: The substances that take part in chemical reaction are called reactants.
2. Products: When reactants are combined together they formed new substances are called
products.
Example:- H2 + O2 H2O
Reactants Product
Steps for writing a chemical equation:
1. The reactants are written on the Left Hand Side with a plus (+) sign between them.
2. Then draw the symbol of arrow and head of arrow towards the products and shows the
direction of reaction.
3. Now, products are written with a plus sign (+) between them in Right Hand Side.
N2 + H2 NH3
Unbalanced equation: When the number of atoms of each element in reactants are not equal to the
number of atoms of each elements in products, is called unbalanced chemical equation. It is also
known as skeletal equation.
Examples : H2 + O2 H2O
N2 + H2 NH3
Balanced equation: When the number of atoms of each element in reactants are equal to the number
of atoms of each elements in products, is called balanced chemical equation.
Examples : 2H2 + O2 2 H2O
1
CHEMICAL REACTION AND
CHAPTER NAME EQUATION
(CHEMISTRY)
, CHEMICAL REACTIONS AND EQUATIONS CLASS X SCIENCE
Chemical Change: The changes in which chemical property of a substance is change is called chemical
change.
Example: 1. Formation of curd. 2. Digestion of food.
3. Burning of fuel like petrol, diesel, wood etc. 4. Rusting of iron.
4. Cooking food 6. Grapes get fermented
Chemical Reaction:-When two or more substances are react together to form one or more new
substances, is called chemical reaction.
Effects of chemical reaction:
1. Always new substances are formed
2. Gas may be released.
3. Heat may be release or absorb.
4. Colour of solution may be change.
5. Metal may be deposited on electrode.
Representation of chemical reaction : Chemical reaction can be represented by two ways :
1. Word Equation : The representation of any chemical reaction in the form of word is called word
equation.
Example : Hydrogen gas combines with nitrogen to form ammonia.
Nitrogen + Hydrogen Ammonia
2. Chemical Equation :- The symbolic representation of any chemical reaction, is called chemical
equation.
Example :- 1. Burning of Coal (C) : C + O2 CO2
2. Burning of Methane : CH4 + O2 CO2 + H2O + Energy
Chemical Reaction has two part :-
1. Reactant 2. Product
1. Reactants: The substances that take part in chemical reaction are called reactants.
2. Products: When reactants are combined together they formed new substances are called
products.
Example:- H2 + O2 H2O
Reactants Product
Steps for writing a chemical equation:
1. The reactants are written on the Left Hand Side with a plus (+) sign between them.
2. Then draw the symbol of arrow and head of arrow towards the products and shows the
direction of reaction.
3. Now, products are written with a plus sign (+) between them in Right Hand Side.
N2 + H2 NH3
Unbalanced equation: When the number of atoms of each element in reactants are not equal to the
number of atoms of each elements in products, is called unbalanced chemical equation. It is also
known as skeletal equation.
Examples : H2 + O2 H2O
N2 + H2 NH3
Balanced equation: When the number of atoms of each element in reactants are equal to the number
of atoms of each elements in products, is called balanced chemical equation.
Examples : 2H2 + O2 2 H2O
1
