Chemical Reaction – Introduction and Characteristics

In this article, we’ll learn about Chemical reactions in detail, but first, let us know about different changes. Let’s begin

Introduction to Changes

The difference observed between the original form of an object/particle/material/matter and the final form is defined as change. Some general examples of changes we see in our daily life are: making airplanes from a sheet of paper, growth of nails, hair, or body, and cooking of food.

Based on the change from the initial to the final form and the changes occurring, the properties changes are classified into two types:

1. Physical changes
2. Chemical changes

Physical Changes

Changes in the physical properties of objects, materials, or substances are called physical changes. Some examples of physical changes are the tearing of paper, melting of ice, formation of ice, and chopping of wood.

Characteristics of Physical Changes:

• In the process of physical change, a new substance or material is not formed.
• Physical change is observed only in the physical state.
• Physical changes are mostly temporary and reversible. It means a product can be returned to its initial form after undergoing some physical change.

Chemical Changes

Changes that occur in the chemical properties of a substance are called chemical changes. Some best examples we see in our daily life are cooking food, burning wood, and explosions of fireworks.

Characteristics of Chemical Changes:

• In the process of chemical changes, a new substance is formed.
• In the chemical change, a new composition is formed.
• Most of the chemical changes are permanent and irreversible.

 

What are Chemical Reactions?

When a chemical change occurs in a substance, we can say that a chemical reaction has taken place. Some examples of chemical reactions are iron rusting, food cooking, and combustion.

How to Identify the Chemical Reaction?

We can identify the chemical reaction by observing the following:

• Change in color
• Change in state
• Change in temperature
• Evolution of gas

Example:

Take a magnesium ribbon. When the magnesium ribbon is burnt in the presence of air, it forms some white-colored powder. The magnesium ribbon is a silvered metal ribbon it turns into powder. It changes its state and color. When the ribbon is burnt in the air, it releases the white-colored flames and turns into a white powder.

Some other examples are fermentation, the routine of eggs, and the ripening of fruits.

How do we represent the Chemical Reaction?

A chemical reaction is represented by writing the initial substances’ names and the final substances obtained. The equation represents the chemical reaction. The word equation is the equation representing the initial and final products of the chemical reaction in a single equation. The word equation represents the substances before and after the reaction in word form, separated by an arrow mark.

Example:

Take the example discussed earlier, the burning of magnesium in the presence of air to form magnesium oxide. In the equation form, we write the above reaction as follows:

Magnesium + Oxygen → Magnesium oxide

Some other chemical reactions we regularly see or observe are the change of milk into curd by fermentation and cooking food. All these reactions are external, and there are some internal chemical reactions; internal here means the reactions in our body. The process of digestion, growth of the organs, and the human body. The chemical reactions that we can see in plants are the process of photosynthesis and respiration in plants.

Applications of Chemical Reaction:

Chemical reactions are very useful as they help us produce the required results, like the digestion of food, and provide energy. In producing the food from plants, the metabolic reactions in the living things.

Drawbacks of Chemical Reaction:

Chemical reactions have a positive side. However, there are some drawbacks as well. Some of them are reactions like rusting make the iron weak and may cause a lot of damage; burning of the wood or trees causes deforestation and pollution.