exothermal

/,eksou'θə:məl/ Cách viết khác : (exothermic) /,eksou'θə:mik/
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exothermal

A student observes an exothermal reaction in a beaker during a chemistry experiment.

Definition
  1. Adjective:
    • Releasing heat during a process: Describes a chemical reaction or physical process that releases energy in the form of heat to its surroundings.
    • Characterized by heat liberation: Pertaining to a compound whose formation from its elements, or a reaction in which it is involved, results in a net output of thermal energy.
Usage
  • The term "exothermal" is used primarily in scientific contexts, especially chemistry, physics, and engineering, to describe processes where heat is a product.
  • It is often used interchangeably with the more common variant "exothermic." Both forms are correct adjectives.
  • It typically modifies nouns like "reaction," "process," "change," or "compound."
Examples
  • Adjective:
    • The combustion of methane is a highly exothermal reaction.
    • When designing the reactor, engineers must account for the exothermal nature of the process.
    • The formation of water from hydrogen and oxygen is exothermal.
Advanced Usage
  • In Thermodynamics: The concept is fundamental in thermodynamics. An exothermal process has a negative change in enthalpy (ΔH < 0), indicating heat is released.
    • In an exothermal process, the system loses heat, so the surroundings get warmer.
  • Safety Contexts: The term is crucial for safety protocols when handling reactive chemicals.
    • Due to the exothermal decomposition of the compound, it must be stored in a cool environment.
Variants and Related Words
  • Exothermic (adj.): The more frequently used synonym for "exothermal." The meanings are identical.
    • The neutralization of an acid with a base is an exothermic reaction.
  • Exothermically (adv.): In a manner that releases heat.
    • The substances reacted exothermically, causing the temperature to rise rapidly.
  • Exotherm (n.): A less common noun referring to the heat released in such a process or a curve on a graph showing such heat release.
    • The differential scanning calorimetry chart showed a sharp exotherm.
Synonyms
  • Heat-releasing: Directly descriptive of the process.
  • Exoergic: A broader term in physics meaning releasing energy, which can include forms other than just heat (e.g., nuclear reactions).
Antonyms
  • Endothermal/Endothermic: Describing a process or reaction that absorbs heat from its surroundings (ΔH > 0).
    • Photosynthesis is an endothermic process.
exothermal

A student observes an exothermal reaction in a beaker during a chemistry experiment.

Adjective
  1. (of a chemical reaction or compound) occurring or formed with the liberation of heat