NOTES
CHEMICAL
REACTION
&
EQUATION
HA M
H UB T
BY S AP A
AJ
PR
, CHEMICAL REACTION:
• The transformation of chemical substance into another chemical
substance is known as Chemical Reaction. e.g.: Rusting of iron, the
setting of milk into curd, digestion of food, etc.
• Chemical changes indicate that a chemical reaction has occured
CHEMICAL EQUATION:
• Representation of chemical reaction using symbols and formulas of the
substances is called Chemical Equation
CHARACTERISTICS OF CHEMICAL REACTIONS:
• Formation of new substances with different properties, Change
in color, Evolution of gas, Evolution or absorption of heat,
Formation of aprecipitate, Irreversibility of many chemical
reactions, Change in state of matter, Change in energy.
BALANCED CHEMICAL EQUATION :
• A balanced chemical equation has an equal number of atoms of
eachelement in the reactant and product side.
• Law of Conservation of Mass: Mass of reactants = Mass of products.
Fe+H₂O → Fe₃O₄+H₂(unbalaced)
3Fe+4H₂O → Fe₃O₄+4H₂(balanced)
NOTE -number of atoms of each element in reactants = number of atoms of
eachelement in products
Balancing Chemical Reaction:
1. Identify the unbalanced equation:
Fe+H₂O → Fe₃O₄+H₂
2. List the number of atoms of different elements in the unbalanced
equation:
CHEMICAL
REACTION
&
EQUATION
HA M
H UB T
BY S AP A
AJ
PR
, CHEMICAL REACTION:
• The transformation of chemical substance into another chemical
substance is known as Chemical Reaction. e.g.: Rusting of iron, the
setting of milk into curd, digestion of food, etc.
• Chemical changes indicate that a chemical reaction has occured
CHEMICAL EQUATION:
• Representation of chemical reaction using symbols and formulas of the
substances is called Chemical Equation
CHARACTERISTICS OF CHEMICAL REACTIONS:
• Formation of new substances with different properties, Change
in color, Evolution of gas, Evolution or absorption of heat,
Formation of aprecipitate, Irreversibility of many chemical
reactions, Change in state of matter, Change in energy.
BALANCED CHEMICAL EQUATION :
• A balanced chemical equation has an equal number of atoms of
eachelement in the reactant and product side.
• Law of Conservation of Mass: Mass of reactants = Mass of products.
Fe+H₂O → Fe₃O₄+H₂(unbalaced)
3Fe+4H₂O → Fe₃O₄+4H₂(balanced)
NOTE -number of atoms of each element in reactants = number of atoms of
eachelement in products
Balancing Chemical Reaction:
1. Identify the unbalanced equation:
Fe+H₂O → Fe₃O₄+H₂
2. List the number of atoms of different elements in the unbalanced
equation:
