For us to understand and comprehend this definition, it is important to know about both Physical and Chemical changes. A perfect example of this is a burning candle. The burning of a candle can be classified as a chemical change, while the conversion of a candle into wax is a physical one. If we dig in more deeper, chemical equations have been developed to simplify expressions of a chemical reaction. 

Now that we have a fair idea of what Chemical Reactions and their components are,  let us discuss a topic slightly more interesting. Did you know that there are a bunch of Chemical Reactions that account for changing the history of the world? These reactions have not only changed the way mankind looks and perceives the world, but they have also become a major landmark in the journey of all of us humans.

Let us enlighten you with a discussion on 6 of these reactions that are renowned and popular to date –  

Polymerisation of Polyethylene

Two scientists, who were trying to react ethylene and benzaldehyde accidentally discovered Polyethylene in 1933.  Instead, they discovered a waxy material that turned out to be a polymer (Substance made up of multiple units) of ethylene. The material was developed as a film and used as insulation for wires and other components. Its structure and manufacturing were a highly guarded secret since it made electrical components light enough to place in planes. Today, polyethylene is the most produced plastic in the world.

Plastic revolutionised the world. They come in various forms and are high in demand since they are easily moulded, resistant to heat, and cheap to make.

Ozone Destruction

While Mechanical refrigeration technology has been in common usage since the 1800s, refrigerators encountered multiple problems due to limited technology. As a solution, two scientists set out to find a much safer refrigerant. As a result of mixing multiple chemicals, chlorofluorocarbons (CFCs) were found to be much safer.

However, CFCs had an unknown problem at the time; their molecules could lead to massive depletion of the ozone layer. Today, they have been replaced with hydrofluorocarbons (HFCs) that are mainly non-toxic and non-flammable.

Synthesis of Urea  

The theory of Vitalism states that living systems are governed by completely different systems than non-living ones. However, Friedrich Wohler, a German Scientist, changed that in 1828. He was working on trying to synthesize ammonium cyanate. When he reacted to various substances to produce ammonium cyanate, he produced white crystals. These were later identified as urea.

This meant that urea was an organic compound and disapproved of one of the basic principles of Vitalism. Later, this laid the foundation for the field of organic chemistry.

Combustion of Hydrogen

In the late 1700s, a new theory came to notice. The concept said that all inflammable substances contained a fire called phlogiston, and during combustion, the phlogiston would be lost to the air. Antoine Lavoisier was a scientist who was very apprehensive of this theory. After a few years, he combusted inflammable air (hydrogen gas) with normal air; the product was water. This experiment laid the foundation for modern chemistry.

Even though Chemistry was an underdeveloped science during those times, water became one of the components where most of the roots of Chemistry are rooted today.

Water with Carbon Dioxide

As you all know, Carbon Dioxide (CO2) is mainly known for its role as a greenhouse gas. However, there is another side to CO2, where it reversibly reacts with water to form carbonic acid. This carbonic acid then breaks down into bicarbonate and then carbonate ions. This acid gives us the sensations in the fresh soda we drink.

In fact, this CO2 reacts the same way with water in the ocean too. The ocean absorbs roughly one-quarter of the CO2 that is released every year.

Saponification

It is a fact that oil and water do not mix well and the reason for this is a theory known as polarity. While water molecules are polar, oil molecules are not. However, this becomes a major problem while cleaning dishes; the grease does not mix with water and stays on the dish.

The answer to this is Soap since its molecules have both polar and non polar parts. While the polar part mixes with the water, the non polar part mixes with oil. This results in the oil forming small droplets in the water that are easily removed. Decades ago, soap was originally made by heating salt, ashes, and animal fats together in water. Today, soap is made by reacting sodium hydroxide/potassium hydroxide with fatty acids.

While these are just a handful of notable chemical reactions, they are essential to know for a student interested in STEM Learning. These experiments give us an idea of how they changed the way we live today and encourage us to keep experimenting and playing around. 

You never know, you may end up writing history!

At ExperiHub, we teach Science and Mathematics by bringing concepts from the real world into the classroom. We conduct science experiments and have myriad science projects for better learning and understanding of concepts. If you want to learn more about Experiential Learning and cool home experiments, browse through our Online Sessions and Youtube Channel!

References: 

“Chemical Reactions and Equations”, BYJUs. https://byjus.com/chemistry/chemical-reactions/

“10 Chemical Reactions that changed the world”, Mark Thomas, 9th May, 2018. https://listverse.com/2018/05/09/10-chemical-reactions-that-changed-the-world/