The chemical Reaction in which an element displaces another element from its solution
Oxidation
Oxidation is the gain of oxygen or loss of hydrogen
Exothermic Reactions
Reaction in which heat is released along with the
formation of products
– Respiration is also exothermic reaction.
– Decomposition of vegetable matter into compost.
Decompositon Reactions
The reaction in which a single substance decomposes to give two or more substances.
Double Displacement Reaction
The reaction in which two different atoms or group of atoms are mutually exchanged
Precipitation Reaction
Any reaction that produces a precipitate is called a precipitation reaction.
Reduction
Reduction is the loss of oxygen or gain of hydrogen.
Chemical Equation
A chemical reaction can be expressed symbolically
by using chemical equation
eg: magnesium is burnt into air to form magnesium oxide can be represented
as
Mg + O2 → MgO
– We can observe or recognise a chemical reaction by observing change
in state, colour, by evolution of gas or by change in temperature.
Physical state of the reactant and products are mentioned to make chemical
reaction more informative. eg: we use (g) for gas, (l) for liquid, (s) for solid
and (aq) for aqueous.
Endothermic Reactions
The reactions which require energy in the form of heat, light or electricty are called Endothermic Reactions
2Ba(OH)2+ NH4Cl → 2BaCl2+ NH4OH
Redox Reaction
The reaction in which one reactant gets oxidised while other gets reduced
Corrosion
When a metal is attacked by substances around it such as moisture, acids etc.
eg. Reddish brown coating on iron.
(ii) Black coating on Silver
Rancidity
When fats and oils are oxidised they become rancid and their smell and taste change.
Antioxidants are added to foods containing fats and oil.
