Exothermic vs. Exergonic — What's the Difference?
Edited by Tayyaba Rehman — By Fiza Rafique — Updated on May 15, 2024
Exothermic reactions release heat and usually increase the temperature of their surroundings, while exergonic reactions release energy in forms other than heat, contributing to the spontaneity of the process.
Difference Between Exothermic and Exergonic
Table of Contents
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Key Differences
Exothermic reactions primarily involve the release of heat, often observed as a temperature rise in the surroundings, whereas exergonic reactions are defined by their release of free energy, which may or may not involve heat.
In exothermic reactions, the total energy of the products is less than that of the reactants, leading to a release of heat energy, while in exergonic reactions, the focus is on the decrease in Gibbs free energy, which is not limited to just heat.
Exothermic processes are commonly associated with burning, combustion, or chemical bonding that produces heat, on the other hand, exergonic processes can include chemical reactions, physical changes, or transport processes that overall decrease free energy.
While exothermic reactions are typically observable through changes like warmth or light, exergonic reactions might not always manifest observable energy changes as they can also involve entropy changes affecting spontaneity without a noticeable energy release.
Exothermic reactions are a subset of exergonic reactions when they result in heat release that leads to a decrease in Gibbs free energy, whereas exergonic reactions encompass a broader range of energy changes beyond just heat, such as work done by the system.
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Comparison Chart
Definition
Reactions that release heat.
Reactions that release energy in forms other than heat.
Energy Change
Decrease in enthalpy (ΔH).
Decrease in free energy (ΔG).
Typical Observations
Increase in temperature.
Spontaneity without energy transfer.
Types of Processes
Combustion, neutralization.
Cellular respiration, photosynthesis.
Dependency on Temperature
Less sensitive.
Highly sensitive.
Compare with Definitions
Exothermic
Characterized by a negative ΔH.
The formation of ice from water releases heat and is exothermic.
Exergonic
Characterized by a negative ΔG.
Spontaneous rusting of iron is an exergonic reaction.
Exothermic
A reaction where heat is released.
Combustion of wood is exothermic as it produces heat.
Exergonic
A reaction where free energy decreases.
ATP hydrolysis in cells is exergonic, providing energy for metabolic processes.
Exothermic
Involves energy transfer to the surroundings.
Exothermic reactions often make their containers feel hot.
Exergonic
Does not necessarily involve heat.
Some exergonic reactions absorb heat but still proceed spontaneously.
Exothermic
Common in everyday chemical processes.
Neutralization reactions between acids and bases are exothermic.
Exergonic
Important in biological systems.
Photosynthesis is exergonic and drives the growth of plants.
Exothermic
Usually results in a temperature increase.
Mixing of sulfuric acid and water is exothermic and warms the solution.
Exergonic
Often linked to increased entropy.
Melting of ice is exergonic due to the increase in entropy.
Exothermic
Releasing heat
An exothermic reaction.
Exergonic
Releasing energy.
Exothermic
That releases energy in the form of heat.
Exergonic
Releasing energy (especially as heat)
Exothermic
That releases heat during its formation, and absorbs it during its decomposition.
Exothermic
(zoology) Of an animal: whose body temperature is regulated by external factors; cold-blooded.
Exothermic
Characterized by, or formed with, evolution of heat; as, an exothermic reaction; - opposed to endothermic.
Exothermic
(of a chemical reaction or compound) occurring or formed with evolution of heat
Common Curiosities
What types of energy changes occur in exergonic reactions?
Exergonic reactions may involve changes in thermal, chemical, or potential energy.
What is an exothermic reaction?
An exothermic reaction is a chemical process that releases heat, often observed as warmth.
Can exothermic reactions be non-exergonic?
No, all exothermic reactions are exergonic because they involve energy release.
How does temperature affect exothermic and exergonic reactions?
Temperature changes can affect the rate and spontaneity of these reactions, with exergonic reactions being more sensitive to temperature shifts.
What is an exergonic reaction?
An exergonic reaction is a process where the system's free energy decreases, enhancing spontaneity.
Why is it important to understand the difference between exothermic and exergonic?
Understanding these differences helps in predicting the behavior of chemical reactions and their impacts on the surroundings.
What is an example of an exergonic reaction in nature?
The decomposition of organic matter in soil is an exergonic process that releases nutrients.
Can exothermic reactions occur at all temperatures?
Yes, exothermic reactions can occur at various temperatures, although the rate may differ.
Are all exergonic reactions also exothermic?
No, not all exergonic reactions are exothermic; some may involve the absorption of heat.
How are exergonic reactions beneficial to living organisms?
Exergonic reactions provide the necessary energy for various biological functions, such as muscle contraction and nerve transmission.
What is an example of an exothermic reaction in daily life?
Burning natural gas in a stove is an example of an exothermic reaction providing heat for cooking.
How do catalysts affect exothermic and exergonic reactions?
Catalysts lower the activation energy required for these reactions, making them proceed more quickly but without altering the overall energy release.
What distinguishes an exothermic reaction from other types of reactions?
Exothermic reactions uniquely release heat, making them easily identifiable through temperature change.
What role do exothermic reactions play in the environment?
Exothermic reactions, like combustion, significantly contribute to heat generation in natural and industrial processes.
What distinguishes an exergonic reaction from other energy changes?
Exergonic reactions are characterized by a decrease in free energy, which is critical for determining reaction spontaneity.
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Fiza RafiqueFiza Rafique is a skilled content writer at AskDifference.com, where she meticulously refines and enhances written pieces. Drawing from her vast editorial expertise, Fiza ensures clarity, accuracy, and precision in every article. Passionate about language, she continually seeks to elevate the quality of content for readers worldwide.
Edited by
Tayyaba RehmanTayyaba Rehman is a distinguished writer, currently serving as a primary contributor to askdifference.com. As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.
