Chemical reactions

Sant Nischal Singh Public school

PPT Presentation On chemical reaction

And its types

Submitted by Submitted toSamar kansal Mr. Manish sirRoll no.38 (subject in charge)

What is a chemical reaction Types of chemical reactions Combination reactions Decomposition reactions Displacement reactions Double displacement

reactions

contents

A chemical process(or change ) in which certain substances react together to form some new substances having different properties is called a chemical reaction. The substances which take part in a chemical reaction are called reactants and the substances formed in a chemical reaction are called products . In a chemical reaction, the amount of reactants decreases whereas that of products increases with time, until the reaction is over.

What is a chemical reaction?

We have studied that the chemical involves simply the exchange of partners in the reactants to form products. Neither the atoms disappear from the reaction mixture nor new atoms appear in the same. In fact, the chemical reaction bonds present in the reacting species break and new bonds in the product species are formed.Chemical reaction are classified into 5 types. They are:-1.Combination reactions 2.decomposition reaction3displacement reactions 4.double displacement reactions 5. Oxidation and reduction reactions

Types of chemical reactions

Combination reactions may be defined as :The reaction in which two or more substances combine to form a single substance under suitable conditions.In these reactions, the combination may be takes place between Two or more elements Two or more compounds Elements and compoundsFor example:- combustion of coalC(s) + O2 ----> CO2

Combination reactions

Decomposition reactions may be defined as : the reactions in which a single substance splits into two or more simple substances under suitable conditions.The decomposition reactions are mostly endothermic in nature. Energy in the form of heat, light or electricity is generally absorbed in these reactions. It causes the cleavage or breaking of the bonds in the reacting substances which decompose to give the products.For example :- Decomposition of potassium chlorate 2KClO3 ---- 2KCl + 3O2

Decomposition reactions

Displacement reactions may be defined as : the chemical reactions in which one element takes the position or place of another element present in a compound. The displacement reactions are very common in the metals. Normally, a more reactive metal displaces a less reactive metal present as its salt dissolved in water. The reaction is often known as metal displacement reaction.For example :- zinc displaces iron from the aqueous solutions of ferrous sulphateZn + FeSO4 ----- ZnSO4 + Fe

Displacement reactions

Double displacement reactions may be defined as : the chemical reaction in which one component each of both the reacting molecules get exchanged to form the products. This means that double displacement has taken place .For example :- A white precipitate of barium sulphate is immediately formed as a result of double displacement reaction BaCl2 + Na2SO4 ------ BaSO4 + 2NaCl

Double displacement reactions

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