Exothermic Reaction - Meaning, Definition, Examples, Causes, FAQs

Define Exothermic reaction.

Exothermic Definition: Exothermic meaning is a chemical reaction that involves the release of energy in the form of heat or light is known as an exothermic process. These reactions are the opposites of endothermic reactions, and they can be written as follows in a chemical equation: Products + Reactants + Energy. As a result, it's easy to see how the net amount of energy required to start an exothermic process is less than the net amount of energy released.

The net quantity of heat energy that passes through a calorimeter, an instrument used to quantify the heat released by a chemical reaction, is equal to the negative of the total energy change of the system. However, measuring or even calculating the absolute total of energy in a chemical system is extremely challenging. As a result, the energy change (also known as the enthalpy change and indicated by the letter H) is measured instead. The following equation describes the relationship between the value of H and the reaction's bond energies.

ΔH = (energy used in the creation of bonds that result in products) - (energy released when the reactant bonds are broken)

As a result, it is clear that the change in enthalpy for an exothermic reaction will always be negative, i.e. ΔH < 0.

Bomb calorimeters are excellent tools for determining the enthalpy change of combustion reactions.

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Exothermic Reaction Examples

The following are some instances of exothermic examples that occur in everyday life:

1. Exploding a firecracker — one of the greatest illustrations of an exothermic reaction is the bursting of a firecracker, which produces a loud bang as well as light and heat.

2. Lighting a candle - this is a continual reaction in which the wax works as fuel and burns for a long time.

3. When you turn on a light bulb, the electric current induces a reaction in the tungsten filament, which produces light and heat.

4. Fuel combustion - whether in a car engine or a gas stove, fuel combustion is an exothermic reaction. The heat created is utilized for a variety of reasons, including operating a motor, cooking, and so on.

5. When hydrogen is used in hydrogen-oxygen fuel cells, it undergoes combustion and produces an electric charge, which is an exothermic reaction.

6. Another example of an exothermic reaction is the combustion of natural gas methane. Exothermic reaction examples equations:

CH₄+2O₂→CO₂+2H₂O

Many more examples of this type of reaction can be found in the environment. The trick is to determine if these processes emit energy into the environment in the form of light, heat, or, in certain situations, sound. Acid and alkali neutralization reactions, water and reactive metals, and weakly reactive metals with strong acids are some of the more advanced varieties of such reactions. Self-heating technology also makes advantage of exothermic reactions.

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Combustion

Combustion is the process of burning in which a fuel undergoes reduction and oxidation in order to release energy in some form. Combustion is demonstrated by lighting undesirable papers with kerosene and a matchstick. To put it another way, combustion is anything that burns and releases energy. As oxygen is such an important element in burning, it plays an important role as an oxidizing agent in most types of combustion.

It does, however, produce dangerous by-products such as smoke and ash. By-products like these are one of the most common sources of air pollution. Farmers' stubble burning in various northern Indian states in late 2019 resulted in substantial amounts of smog (a mixture of smoke and fog). This had a negative impact on the state of New Delhi's atmosphere, causing its air quality to plummet to dangerously low levels.

Detonation of Nitroglycerin

Nitroglycerin is a flammable chemical that is commonly used in the manufacture of explosives. Its highly flammable physical qualities, which allow it to catch fire quickly and easily, make it a desirable component for explosives and dynamite. For combustion, it is frequently combined with another fuel. When nitroglycerin is detonated, it causes the surrounding fuel to burn, resulting in a shockwave that can travel at 30 times the speed of sound.

The detonation itself is an exothermic process since it produces a large amount of gases and a very high temperature (upwards of 5,000 degrees Celsius). The physical properties of nitroglycerin allow it to disintegrate and release huge amounts of energy during combustion. It's for this reason that it's the favored chemical in high-explosive devices.

Nuclear Fission of Uranium-235

Uranium-235 fission is another example of an exothermic process. Fission releases energy in the form of heat and gamma rays when it occurs. This energy can be used in a variety of businesses. The reaction also produces nuclei and neutrons, which must be appropriately eliminated to avoid contamination of the environment. Uranium nuclear fission is a high-profile reaction that must be carried out in carefully regulated conditions.

It is also one of the most efficient ways of disseminating energy, producing 2.5 million times the energy produced by coal combustion, which is one of the most popular varieties nowadays.

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Neutralization Reactions

These are reactions in which both acidic and basic components are involved in the combustion. As a result, by-products such as salt and water are formed. Neutralization reactions are named such because they neutralize the pH of the interacting components.

What Causes Respiration to be an Exothermic Process?

The process through which people take in oxygen and exhale carbon dioxide is known as respiration. The following is the chemical equation for this procedure:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy

It's worth noting that C₆H₁₂O₆ is the formula for glucose, which mixes with the oxygen inhaled by humans to produce carbon dioxide, water, and energy. As of the energy released during the reaction, respiration is an exothermic reaction.

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