Chemical Change-Conditions For A Chemical Change

Chemical changes result from changes in the chemical composition of the world around us caused by the response of substances. They occur when two or more substances combine to form a new substance, called chemical synthesis or decomposition into two or more different substances. Some chemical changes are beneficial, such as the formation of fertiliser when organic material such as plant matter breaks down into inorganic material such as carbon dioxide and water, which are then used to fertilise the soil.

Chemical Change:

Chemical changes are referred to as an irreversible process since the reaction can not be reversed unless chemical reactions are used to do so. An example of chemical change is the formation of precipitates caused by chemical reactions and the formation of gases resulting from changes in temperature or pressure. 

Examples of Chemical Changes:

Everyday processes like burning a candle/paper/wood log, digestion, cooking/baking, using a chemical battery, electroplating, curd formation, rotting, acid-base reactions, rusting are all examples of chemical changes.

Types:

The chemical changes are classified into three subdivisions:

Inorganic Chemical Changes

Organic Chemical Changes

Biochemical changes

Organic Chemical Changes:

Organic compounds refer to the complex covalently bonded carbon compounds that take part in various chemical reactions and cause a chemical change. Below are a few examples:

Burning of Methane:

Methane is also known as natural gas, used as a fuel nowadays.

When we burn methane and oxygen in the air, it releases water and carbon dioxide into the atmosphere. This is a clear example of a combustion reaction representing a chemical change.

Ripening of fruits:

Excess ethylene is produced in fruits when they are damaged. This results in the production of enzymes in the fruits that react with a chemical present on the fruit, due to which the fruit goes through numerous changes. These changes are chemical changes.

Inorganic Chemical Changes:

The chemical reactions that do not involve the usage of complex organic compounds and only include inorganic compounds are called inorganic chemical changes. Below mentioned are a few examples of the inorganic chemical changes:

Making of steel

Many elements are added to indefinite iron amounts in forming steel, where carbon forms the base. Substances with different properties than that iron initially have are formed, which indicates that this is a chemical change.

Firework Lightning

Nitrates of several metals form the fireworks. When the fireworks are lit up, it leads to a combustion reaction, which forms new substances when heat/light is emitted. This formation of new substances indicates a chemical change.

Biochemical changes:

Biochemical changes include reactions based on various living organisms like reptiles, humans, mammals, plants etc. Below mentioned are a few examples under this category:

Photosynthesis

In this process, sunlight and oxygen are used to form glucose and carbon dioxide. This means that light energy changes into chemical energy. Since a chemical reaction is involved in this process, it is referred to as a chemical change.

Conditions for a chemical change:

Below mentioned are the six conditions for a chemical change to take place:- 

The molecules that have to be combined should be in close contact with each other, which means they should either be touching or mixed.

There should be an energetic collision between the molecules of reactants in the correct pattern or orientation to break the previous bonds to form new ones. 

The high energy that is used in the collision is called activation energy. This energy may be in heat, electricity, light or a catalytic form.

The amount of heat or pressure required for the reaction to occur should be available.

A few reactions take place only when the reactant is in the form of a solution. Hence, they should be brought in dilute form.

The reaction should be performed in a lit-up room since some reactions require light to show results.

Signs of a chemical change:

Let us have a look at some of the main pieces of evidence for a chemical change:

• Change in colour, precipitate formation, gas formation.
• Change in odour.
• Change in temperature, the energy is given off or absorbed.
• Changed composition, organic matter getting decomposed and irreversible behaviour.

Conclusion:

In this article, we know that a chemical change is a change in which an entirely new substance is formed. These changes can not be reversed. We also study the chemical changes, namely organic, inorganic and biochemical changes, in this article. Examples of chemical changes have also been discussed. Further, we discuss all the conditions of the chemical changes. We end the article by briefly mentioning the evidence that proves the presence of a chemical change.