study circle: NCERT Chapter 1 science 10th class notes

CHEMICAL EQUATION

in nature there occur thousand of reactions,some of them are physical and other chemical.

physical reaction are those in which there occur change in physical state only and chemical composition of substance remain unchanged.

&chemical reaction are those in which chemical composition of substance gets changed and new substance formed ..

During chemical reaction there can be 1)change in state 2)change in colour 3)evolution of gas 4)change in temperature etc.

Chemical reaction are following types-

1)combination reaction 2)decomposition reaction 3)displacement reaction 4)double displacement reaction 5)redox reaction

Electrolysis of water is a decomposion reaction in which water is decomposed into H2 and O2 under influence of electric current.

there are certain reaction which take place only in presence of light .such reaction are called photochemical reaction.

the more reactive element can displace less reactive element from there salt solution,such reaction are called displacement reaction.

the substance which prevent oxidation are called antioxident and are added to food articals to prevent there oxidation./spoilage.

1)CHEMICAL EQUATION-when a chemical change is represented in the form of symbol and formula.

2)CHEMICAL REACTION-a change in which one or more chemical element or compound from new compound.

3)BALANCE CHEMICAL EQUATION-a chemical equation with same no of atoms of each element type of reactant as well as product side.

4)REACTANTS-the substance which react with each other to form a new substamnce.

5)PRODUCTS-the substances formed as a results of a chemical change.

6)EXOTHERMIC REACTIIONS-chemical reactions which are accompained by release of heat energy .

7)ENDOTHERMIC REACTIONS-the chemical reactions which are accompianed by absorbation of energy.

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