Chemical Reactions and Equations Class 10 Notes

What is Chemical Equation?

A chemical equation is the symbolic representation of a chemical reaction which is represented in the form of symbols and formulae. The main features

of a chemical equation is as follows:

• The reactants of an equation are written on the left-hand side.
• The products obtained is written on the right-hand side.

Here is an example of a chemical equation:

H ₂ + O₂  → H ₂

(Reactants) (Product)

What is Chemical Reaction?

Chemical Reaction is a process of transformation or rearrangement of the chemical substance into a new chemical substance by breaking of bonds between atoms and changing its physical form. Baking a cake, cooking an egg, mixing baking soda and vinegar to produce salt and carbon dioxide gas are few examples of chemical reactions.

Balancing a Chemical Equations

According to the law of conservation of mass, a mass can neither be created nor destroyed. We need to balance a chemical equation without changing the number of atoms of each element. Therefore, the total mass of the elements present in the products of a chemical reaction has to be equal to the total mass of the elements present in the reactants.

For example:

Lead + Lead oxide + sulphuric acid à Lead sulphate + Water.

The balanced chemical equation is written as:

Pb + PbO₂ + H₂SO₄ → PbSO₄ + H₂O

Types of chemical reactions

There are five main types of chemical reactions. Listed below are the types of

chemical reactions:

1. Combination Reaction.
2. Decomposition Reaction.
3. Double Displacement Reaction.
4. Oxidation Reaction.
5. Reduction Reaction.

Few Important Questions

• What is Corrosion?
• What is a Chemical Equation?
• What is a Combination Reaction?
• Explain precipitation reaction with suitable examples.
• Write the balanced equations for Zinc metal + Oxygen gas →  Zinc oxide.

Access NCERT Solutions for class 10 Science Chapter 1 Chemical reactions and equations

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