Question

Explain chemical reaction and chemical equation with one example

Answer 1

The process is which the reactants reacts and give a product is know as chemical reaction .


The method of writing a chemical reaction by using formulas and symbols of reacts and the product formed ...Is known as chemical equation

Answer 2

Chemical Reaction is the process in which atoms of some elements rearrange - that is , undergo a chemical change - to form a new product with different properties,​ This involves breaking of old bonds between the reacting atoms and making of new chemical bonds between the rearranged atoms..

For example :- The burning of Magnesium ribbon in air . In this reaction, Magnesium ribbon, on heating , combines with oxygen to form a white powder of Magnesium oxide, which is totally different in it's properties from magnesium and oxygen.


2Mg (s) + O2 (g) —» 2 Mgo (s)

physical state of reactants and products can be shown by writing (s) for solid, (l) for liquid, ( aq) for Aqueous solution, and ( g) for Gaseous substances after it's formula or symbol in chemical reaction.

Two observations that may suggest that a chemical reaction has taken place are :

» Evolution of Gas .
» Change in temperature.

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The method of representing a chemical reaction with the help of symbols and formulae of the chemical Substances involved in it is known as Chemical Equation..

For example :- zinc metal reacts with dilute sulphuric acid to form Zinc sulphate and hydrogen gas .

This can be represented by chemical equation as follows :-

Zn (s) + H2SO4 (aq) —» ZnSO4 (aq) + H2 (g)

Balanced chemical Equation :
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» A balanced chemical Equation has an equal numbers of atoms of different elements in the side of reactants and products.

» In a balanced chemical equation, the sum of masses of the reactants is equal to the sum of masses of the product.

» It obeys law of conservation of mass.

» Example :-

Zn (s) + H2SO4 (aq) —» ZnSO4 (aq) + H2 (g)

here, number of Zn, H, S and O are same in both reactants and products side.

Unbalanced Chemical Equation :
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» A Unbalanced chemical Equation has an unequal numbers of atoms of one or more elements in the reaction.

» In an unbalanced Chemical Equation, the sum of masses of the reactants is not equal to the sum of the products .

» It does not obeys the law of conservation of mass.

» Example :- H2 + O2 — » H20

here, one oxygen atom is more in reactants side than in product side. it means one atom of oxygen is being destroyed, which is violation of law of conservation of mass.

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