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.

Learn more about Chemical Reactions and Equations from the topics given below:

Practise This Question

Two elements X and Y need to be arranged in Mendeleev's periodic table. X has 3 protons more ​​​​​than Y but their neutrons are equal in number. Which of the following is correct about X and Y?