# Chemical Equations

## Chemical Equations In previous sessions, we learned about chemical reaction, different signs that represent chemical reaction and reason behind the happening of chemical reaction.

Learning Sessions:

With this session we will learn about chemical equations. We will focus on three topics:

• What are chemical equations
• How to write a chemical equation
• Symbols in chemical equation

What are chemical equations

Chemical Equation is a symbolic representation of chemical reaction, where the reactants and the products are expressed through formula & symbols. Whenever any chemical reaction happens we need to do present that reaction in the form of equation, where we can identify the reactant that take apart in reaction and the products formed during the chemical reaction. We get a complete representation of balanced chemical equation which help us to understand how the chemical reaction is move on.

A chemical equation has three parts.

1. Reactant – Starting elements or compounds to take part in reaction. They are mentioned on left hand side of equation
2. Product – New element or compound formed during chemical reaction.  They are mentioned on right hand side of equation
3. Coefficient – A number in front of reactant or product to make balanced chemical equation

Hydrogen gas reacts with Oxygen and  form Water.

Hydrogen and Oxygen both are reactants, which allow to take part in chemical reaction and when both get combined together they form water molecules.

Water is the end product
Number 2 mentioned in front of reactants and products is a coefficient to balance the atoms in reactant and product. Balancing is done according to the rule of Conservation of Mass.

How to write a chemical equation

There are three basic steps to write a chemical equation.

• Step 1
• Identify reactants & products
• Put reactants on left side & products on right side
• “→” means yields. Direction in which chemical reaction is moving

• Step 2
• Use the correct formulas like H, O, N, Cl, Br, I and F
• Represent states of matter – (s), (l), (g) or (aq)

• Step 3
• Balance the chemical equation using coefficients
• Follow the Law of Conservation of Matter