Question 1 What is a chemical equation?

Question 2 Give an example of chemical equation?

Question 3 What is a balanced equation?

Question 4 What is an unbalanced equation?

Question 5 What are the steps of balancing the equation?

**Chemical Equation
**

The method of representing a chemical reaction with the help of symbols and formula is called chemical equation.

**For Example :**

Zinc + Sulphuric acid → Zinc Sulphate + Hydrogen

Reactants Products

The reactants are always written on left hand side in an equation with a plus sign between the.

The products are always written on right hand side in an equation with a plus sign between them.

A chemical equation is the short hand method of representing chemical reaction.

**Balanced Equation**: It has equal number of atoms of different elements in reactants and products.

Atom |
Reactant |
Product |

Zn | 1 | 1 |

H | 2 | 2 |

S | 1 | 1 |

O | 4 | 4 |

Unbalanced Equation: It has unequal number of atoms of different elements in reactants and products.

H_{2} + O_{2} → H_{2}O

Atoms |
Reactants |
Products |

H | 2 | 2 |

O | 2 | 1 |

**Balancing of Chemical Equation**

The process of making the number of different types of atoms equal on both side of an equation is called balancing equation.

**Steps to balance chemical equation**

(1) Write down the chemical reaction in the form of word equation, keeping reactants on left hand side and products on right hand side.

(2) Write symbol and formula of all reactants and products in word equation.

(3) Balance the equation by multiplying the symbols and formula by smallest possible figures.

(4) Make the equation informative by indicating physical state, heat changes, reaction condition.

(5) Indicate the physical state of reactant and products in an equation. We use the symbols as: solid(s), liquid(l), gas(g).

**Example of balancing the equation**

**(1) **CH_{4 +}O_{2 }→ CO_{2 +}H_{2}O

Step 1) Make H atoms equal(Multiply products by 2)

CH_{4 +}O_{2 }→ CO_{2 +2}H_{2}O

Step 2) Multiply oxygen of reactants by 2

CH_{4 +}_{ }** _{2}**O

_{2 → }CO

_{2 +}

_{2}_{ }H

_{2}O

_{Balanced equation}

**(2) **(Cu)_{2}SO_{4} + NaOH →** **Cu(OH)_{2+}Na_{2}SO_{4}

Step 1) Multiply sodium hydroxide by 2

CuSO_{4} + 2 NaOH → Cu(OH)_{2 }+ Na_{2}SO_{4 Balanced equation}

** (3) **Fe +_{ }H_{2}O → Fe_{3}O_{4 + }H_{2}

Step 1) Multiply Fe by 3 on left hand side

3 Fe_{+ }H_{2}O → Fe_{3}O_{4 + }H_{2}

Step 2)Multiply oxygen by 4 on left hand side

3 Fe_{+ 4 }H_{2}O → Fe_{3}O_{4 + }H_{2}

Step 3)Multiply hydrogen by 4 on right hand side

3 Fe_{+ 4 }H_{2}O → Fe_{3}O_{4 +}_{4 }H_{2 }_{ Balanced equation}

**Other Notes from Chapter 1 Chemical Reaction and Equation**

- Chemical Reaction and Equation
- Characteristics of Chemical reaction
- Combination reaction
- Decomposition reaction
- Displacement Reaction
- Double Displacement Reaction
- Oxidation and Reduction reaction
- Effects of oxidation Reaction in Everyday Life

santanu mandal. says

Nice many many thanks for it.

admin says

Welcome

Krunal Dhapodkar says

Mam pls makes this notes for social science also pls

Milind says

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Although teachers are taking lot of efforts to educate the students, it is equally important for the student to do the home work sincerely and gather knowledge from other resources, like yours.