Real life examples of Exothermic Reactions

Exothermic reaction is a heat generating chemical reaction. Exothermic is basically Greek word meaning exterior, while the appendage ‘thermic’ means ‘heat’. As a chemical process, exothermic means heat moving outside. Scientists take up exothermic reaction as crucial to fire and explosion studies. In most of the experimentations in forensic science, exothermic reactions are important.

Exothermic reactions take place in different activities of day-to-day life and living. The only difference is the speed at which such reactions take place. For instance, when a single piece of iron begins rusting, this reaction takes place, although it is in a mild form. Another example is when boiling of water takes place, heat from oven is essential for it. The normal temperature of the room would not make the water boil. So boiling water is an endothermic experience. But when the same water starts letting out heat and begins freezing, the exothermic reaction begins and water finally becomes ice cubes. Physical Chemistry tells us that in an exothermic reaction, the temperature of the surrounding objects goes on increasing, when the exothermic process lets out heat. But the endothermic process takes up heat and makes the surroundings in the atmosphere cool. Let’s take some of the interesting real life examples of exothermic reactions. Either we see such reactions in common incidents of our lives or in the ordinary experimentations in the laboratory by the school and college students.

Making of ice-cube

Everyone knows when melting of ice takes place, it is an endothermic reaction. Now we would take this just in the other way; when we put water in an ice tray and keep it in the refrigerator, water begins letting out heat and cools down only to become ice-cubes, it becomes an exothermic reaction. But what happens to the heat in the water? It gets transferred to the environment through the compressor in shape of air.

The compressor has coils in the coolant loop to help passage of heat through those  wires and for this reason compressor stays at the back of the refrigerator. Another example is anyone could freeze water just by keeping dry-ice and liquid nitrogen in it. The dry ice would immediately begin vaporizing, while the liquid nitrogen would boil. Consequently, the water would freeze, indicating that both liquid nitrogen and ice-ice are getting thermal heat.

Snow formation in clouds

Formation of clouds is clearly an exothermic reaction. Clouds come into existence from condensation of water vapor. Some clouds even have ice and there we get the heat from condensation as well as crystallization. For exothermic is always the process that lets out energy in the shape of heat.  As a matter of fact, in this chemical process, heat generated as energy is always a by-product.

Does burning of a candle cause exothermic reaction?

The body of the candle consists of paraffin, which is hydrocarbon. When paraffin burns with the flame, it creates reaction with oxygen to create carbon dioxide and water. This reaction is certainly exothermic as it lets out heat to the atmosphere with other products. The amount of heat depends on the chemical reaction between the hydrocarbon and oxygen. Oxygen is available in thick quantity at the outer edge of flame, while atmosphere is the source of oxygen.

Rusting of iron

As it goes without any doubt, rusting of an iron is a chemical reaction. Iron gathers oxidization at a very slow pace. So rusting is an exothermic reaction between iron and oxygen. Rusting takes place when iron is in pure form or it is alloyed. Heat gets released during this process when iron comes in contact with oxygen.  Rusting is basically the formation of chemical substance that takes place due to formation of moisture on the iron. The chemical formula for this goes as Fe2O3.xH2O.

Is burning of sugar exothermic?

Sugar goes through a chemical reaction inside human body. As it forms by combination of carbon, oxygen, and Hydrogen, it gives heat once it goes inside human body resulting in energy. The heat goes out of human body and gets added to atmospheric heat. This is surely an exothermic reaction, although few doubt this to be endothermic. When we put sugar in a dish and burns it by a flame it dissolves generating heat. Quantity of energy released by it is huge and it is an exothermic reaction.

Formation of ion pairs is exothermic

Ions when those are in gaseous form make intense interaction with water only to result in hydrated ions. This remains always a very exothermic process. The smaller gets the ion radius, the bigger is the ion charge. As a result ion hydration enthalpy grows larger, resulting in intense exothermic reaction.

Reaction of Strong acid and Water?

Usually, heat is necessary to break a chemical bond. But when a chemical bond forms, it releases energy.  Just take instance of bond formation, which is always an exothermic reaction. HCI is the form of strong acid and when it gets dissolved in water, the hydrogen ion reacts with water to make a more complex reaction. As the hydrogen ion is very small in size, large amount of energy generated gets concentrated in a relatively smaller area. It draws the polar water molecules. The hydrogen ions resulting in formation of covalent bond with water, also attract a number of strong hydrogen bonds. So this becomes a strong exothermic process. This takes place when strong acid gets mixed with water.

Do water and calcium chloride bring an exothermic reaction?

Students often make this experiment in their labs. The result is it always becomes an exothermic reaction. Calcium chloride, water, and baking soda mixed together produce rise in temperature by letting off heat to the atmosphere.

Cold packs to heal an injury

Another common example of exothermic reaction is the cold pack that we apply to the place of pain after an injury.  The cold pack has an inner bag and outer bag. The inner bag contains water, while the outer bag has ionic salts in it. When we press the cold pack, the water from inner bag comes in touch with ionic salt and the result is those let out heat.  Thus heat released to the atmosphere is an example of exothermic reaction.