Chemistry

Chapter 1

Chemical Reactions And Equations

Some Important Headings and Its Defination with Example

1. Chemical Reaction

A chemical reaction is the process by which reactants react with each other to yield products. In chemical reactions, the reactant molecules are completely different from the molecules of the products formed.

Example

Hydrogen gas reacts with oxygen gas to form Water as product

2. Chemical Equation

A chemical Equation is a written Representation of a Chemical Reaction

Types of Chemical Reactions

There 4 types of chemical Reactions which are given below

(1) Combination Reaction

A combination reaction is a reaction where two or more elements or compounds combine to form a single compound. Such reactions are represented by equations of the following form:

Example

Magnesium reacts with Oxygen to form Magnesium Oxide

2Mg + O₂ ————–> 2MgO

Combination Reaction is Also Known As Synthesis Reaction.

Some more example of Combination Reaction

2. Decomposition Reaction

Decomposition is a type of chemical reaction.  It is defined as the reaction in which a single compound splits into two or more simple substances under suitable conditions

Example

Breaking of Sodium Chloride into Sodium and Chlorine

Nacl ————–> Na+Cl

Some more Example of Decompostion Reaction

Note:- The Decomposition Reaction May be Either Exothermic or Endothermic.for Example

• The decomposition of NO to N₂ & O₂ is exothermic.
• Decomposition of ozone (O₃) to oxygen (O₂) is exothermic.

3. Displacement Reaction

Single displacement reactions are reactions where one reactant replaces part of the other:

AB + C → AC + B

An example is the reaction between iron and copper sulfate to produce iron sulfate and copper:

Fe + CuSO₄ → FeSO₄ + Cu

Some more Example of Displacement Reaction

4. Double Displacement Reaction

Those reactions in which two compounds react by an exchange of ions to form two new compounds are called double displacement reactions. In double replacement reactions, the positive ions exchange negative ion partners. Many double displacement reactions occur between ionic compounds that are dissolved in water. A double replacement reaction is represented by the general equation

We can write as

Example

AB+CD ———-> AD+BC

Example

BaCl₂ +2AgNO₃ ——— 2Agcl +Ba( NO₃ ) ₂

Some more Example of Double Displacement Reaction

* Oxidation

The Addition of oxygen to a substance or removal of Hydrogen from a substance know as oxidation.

Example

2Mg + O₂ ——— 2MgO

* Reduction

The removal of Oxygen from a substance or Addition of hydrogen to a substance known as Reduction

Example

Reducing Agent

A substance which loses electrons to other substances in a redox reaction and gets oxidized to the higher valency state is called a reducing agent

Example

Oxidising Agent

An oxidizing agent is a substance in a redox chemical reaction that gains or “accepts”/”receives” an electron from a reducing agent. In other words, an oxidizer is any substance that oxidizes another substance

Example

Redox Reaction

An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron. Redox reactions are common and vital to some of the basic functions of life, including photosynthesis, respiration, combustion, and corrosion or rusting

Example