Chemical reaction and equation class 10th (Notes)

Chemical reaction

 Chemical reaction are the process in which a new substance having a new property are formed .

 Unbalanced chemical  equation

 In  unbalanced chemical equation,  number of atom of each type in reactant side (LHS) is not equal to the number of atoms in product (LHS).

Balanced chemical equation

 in chemical equation in which the number of all the atoms on LHS and RHS is equal is called balanced chemical equation

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 Balancing of chemical equation

 the process of balancing an unbalanced equation is called balancing of chemical equation.

Combination reaction

Those chemical reaction in which two or more substance combine to form a single substance are called combination reaction .

Example

 Mg+O2→2MgO

H2(g)+Cl2(g) →2Hcl(g)

Decomposition reaction

 those reaction in which a single reactant breaks down to give two or more simpler product are called decomposition reaction .

CaCO3(s)→CaO(s)+CO2(g)

Electrolysis

 the process of decomposition of compound in Molten state or in solution by the passage of electric current is called electrolysis.

2H2O(l)→2H2(g)+O2(g)

Exothermic reaction

 those reaction in which heat is released are called exothermic reaction.

Endothermic reaction

 those reaction in which heat is absorbed are called endothermic reaction

N(g)+O2(g)+Heat → 2NO

Photochemical reaction 

Reaction that are brought about by light energy are called photochemical reaction .

Displacement reaction

 those reaction in which one element takes the place of another element in a compound are called displacement reaction .

CuSO4+Zn → ZnSO4+Cu

Double displacement reaction

 those reaction exchange their ions and form two new compound are called double displacement reaction .

BaCl+NaSO4 → BaSO4+NaCl

Oxidation and reduction reactions

Oxidation reaction

 the reaction in which a substance gain Oxygen and losses hydrogen is called Oxidation reaction

 Reduction reaction

 those reaction in which substance gain hydrogen or losses oxygen is called reduction reaction

 Oxidising agent

 the substance which give oxygen for oxidation or remove hydrogen from a substance is called oxidizing agent

 Reducing agent 

the substance which gives hydrogen for reduction or remove oxygen from a substance is called reducing agent

 substance getting oxidized is called reducing agent and the substance getting reduced is called oxidizing agent

 Effects of oxidation and reaction in everyday life

  Corrosion- When a metal is attacked by the substance around it such as humid ,air acids, etc ; the metal is said to be corrode and this gradual process of eating up the metals is called Corrosion .

It is important to know that rusting of iron is a Redox reaction 

Rancidity 

Spoilage of food in such a way that it becomes undesirable for consumption is called rancidity