Chemical equation, Method of writing the essential features of a chemical reaction using chemical symbols (or other agreed-upon abbreviations). By convention, reactants (present at the start) are on the left, products (present at the end) on the right. A single arrow between them denotes an irreversible reaction, a double arrow a reversible reaction. The law of conservation of matter (seeconservation law) requires that every atom on the left appear on the right (the equation must balance); only their arrangements and combinations change.

Chemical equations are a symbolic representation of a chemical reaction that shows the reactants and products involved in the reaction. The NCERT Exemplar for Chemical Reactions and Equations is a comprehensive guide that provides detailed information about chemical equations and reactions.

Heading 1: Importance of Chemical Equations
Chemical equations are important because they provide a concise way to represent chemical reactions. They allow us to understand the chemical changes that take place during a reaction and predict the products of the reaction.

Heading 2: Balancing Chemical Equations
Balancing chemical equations is an important aspect of chemistry. A balanced chemical equation has an equal number of atoms of each element on both sides of the equation. This is important because it ensures that the law of conservation of mass is followed.

Heading 3: Types of Chemical Reactions
There are various types of chemical reactions, including synthesis, decomposition, single replacement, double replacement, and combustion reactions. Each type of reaction has its own unique characteristics and can be represented using a chemical equation.

Heading 4: Stoichiometry
Stoichiometry is the study of the quantitative relationships between reactants and products in a chemical reaction. It involves calculating the amounts of reactants and products involved in a reaction using balanced chemical equations.

Heading 5: Applications of Chemical Equations
Chemical equations have many practical applications, including in the fields of medicine, agriculture, and industry. They are used to produce drugs, fertilizers, and other chemicals. They are also used in the production of energy, such as in combustion reactions.

In conclusion, understanding chemical equations is important for understanding chemical reactions and their applications. The NCERT Exemplar for Chemical Reactions and Equations provides a thorough guide on this topic.