We can know through chemical equations that how substances react each other to form new substances. In this post we will learn what chemical equations are? And how they are balanced. Here we will discuss 10+ examples for class 10 for board exam preparations.
What is a Chemical Equation?
A chemical
equation is symbolic representation of chemical reaction in which reactants produce
products. It is written in the form of symbols and formulas of elements and
compounds.
Example:
H2 +
O2 →H2O
Why Do We Balance Chemical Equation?
According
to ‘Law of Conservation of Mass’ – Mass can neither be created nor be destroyed
in a chemical reaction. So, we must balance the number of atoms of each element
on the both sides.
Rules For Writing a Chemical Equation
1.
Identify the reactants and products.
2.
Write correct formula or symbols of
reactants and products.
3.
Always use + sign between
substances.
4.
Use arrow (→) sign between reactants
and products.
5.
Write physical states of all substances.
6.
Balance the equation
12 Solved Examples of Balanced Chemical Equations
1. Formation of Water
Balanced Equation: 2H2 + O2 → 2H2O
2. Combustion of Methane
Balanced Equation: CH4 + 2O2 →CO2 + 2H2O
3.
Reaction of Iron and Hydrogen
Balanced Equation: 4Fe+ 3O2 → 2Fe2O3
4.
Decomposition of Potassium Chlorate
KClO3 → KCl + O2
Balanced Equation: 2KClO3 → 2KCl + 3O2
5. Reaction of Metal with An Acid
Balanced Equation: Mg + 2HCl →MgCl2 + H2
6. Reaction of Zinc and Sulphuric Acid
Balanced Equation: Zn + H2SO4 →ZnSO4 +H2
7. Reaction of Sodium and Water
Balanced Equation: 2Na + 2H2O →2NaOH + H2
8. Photosynthesis
Balanced Equation: 6CO2 + 6H2O → C6H12O6 + 6O2
9.
Rusting of Iron
Fe+ O2 +H2O Fe2O3.xH2O
Balanced Equation: Balanced equation is based on x value.
10. Thermal Decomposition of Calcium Carbonate
CaCO3 →CaO + CO2
Balanced Equation:
CaCO3 →CaO + CO2
11. Reaction of Aluminium with Oxygen
Al + O2 → Al2O3
Balanced Equation:
4Al
+ 3O2 → 2Al2O3
12. Reaction of Copper and Silver Nitrate
Cu + AgNO3 →Cu(NO3)2
+ Ag
Balanced Equation:
Cu
+ 2AgNO3 →Cu(NO3)2 + 2Ag
Frequently Asked Questions
1.
What are 5 examples of chemical equations?
Answer
1) 2H2 + O2 → 2H2O
2) CH4 + 2O2 →CO2 + 2H2O
3) 4Fe+ 3O2 → 2Fe2O3
4) 2KClO3 → 2KCl + 3O2
5) Mg + 2HCl →MgCl2 + H2
2.
Why do we need to balance chemical equations?
Answer
To follow the law of conservation of mass we need
to balance number of atoms at both sides.
3.
What is a word equation?
Answer
In a
word equation, names of reactants and products are written.
Conclusion
For scoring good marks in Class 10 Science,
student must learn how to write and balance chemical equations.
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