Chemical Reaction When elements or compounds react with some other elements or compounds to form a new compound, it is called a chemical reaction. E.g., zinc reacts with dilute sulphuric acid to form zinc sulphate and hydrogen.
Zn + H2SO4= ZnSO4 +H2
Hydrochloric acid reacts with sodium hydroxide to form sodium chloride and water.
NaOH + HCl = NaCl + H2O
Chemical Equation A chemical reaction may be represented by symbols and chemical formulae. In this representation, reactants are written on the left side and products on the right side with an arrow placed between the reactants and the products. The arrow points towards products. The above-mentioned representation exhibiting the group of reactants and products is called a chemical equation.
Method for writing the chemical equation The method of writing a chemical equation is as below:
Cu + O2= CuO
Balancing a chemical equation According to Dalton's theory, atoms are neither created nor destroyed during chemical changes. Therefore, the number of atoms of reactants and products in a chemical reaction must be equal. Hence, the reaction should be balanced on both sides of the arrow (?). Two methods are in use for the balancing of chemical equations Hit and Trial method and partial equation method. In this article, I am providing you with the other simple and easy method to balance a chemical equation.
CH4 + O2 = CO2 +H2O
aCH4 + bO2 = c CO2 +dH2O
For Carbon: a=c, For Hydrogen: 4a=2d, For Oxygen: 2b=2c+d
Hence a=1 and c=1
On taking second equation:
4a = 2d
4×1 = 2d
Now, on taking third equation:
2b = 2c + d
2b =2×1 + 2
2b = 4
aCH4 + bO2 = c CO2 +dH2O
CH4 + 2O2 = CO2 +2H2O.
Now it is a balanced chemical equation.
If you have any problem you can ask in the comment box below the article.
Advantages of a chemical equationThe following information is gained by a chemical equation:
Hakimuddin Kuwakhedawala is based in India with over 15 years experience as a teacher. Teaching and writing are his passion. Most of the articles of Hakimuddin are related to education, exam, environmental problems, etc.
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We all know that matter can't be destroyed or created. But we can convert one form the matter to another form. Based on this fact only all chemical reactions will be made. The total mass of all the materials which are formed in the reaction should be equal to the mass of all the materials which are involved or taken part in the reaction.
If we take a small equation of water formation ie H2 + O2 = H2O
The materials which are taking part in the reaction are H2 and O2. The product formed in the reaction is H2O.
The mass of the reactants O2 is 32, H2 is 2 and H2O is 18. There are two Oxygen atoms in the reactants and only one in the products. To make them two in the products also a minimum of two water molecules are to be formed
H2 + O2 = 2H2O. Now the oxygen atoms on both the sides are equal. But what about Hydrogen? Now in the products, there are 4 Hydrogen atoms. So you should have 4 Hydrogen atoms on the reactants side also. Now the reaction has to be written as 2 H2 + O2 = 2H20. 4 atoms of Hydrogen and 2 atoms of Oxygen took part in the reaction. The same number of Hydrogen and Oxygen atoms are in products also. If you take the mass into consideration, the total mass of reactants is 2X2 + 2 X 16= 4+32 = 36. The total mass of products is 2 X 18 = 36.
In this way also one can balance the chemical reaction.
The author has explained the reaction balancing concept very well and it will be very useful to the students. He has also narrated the importance of writing chemical reactions also.