Are Exothermic Reactions a Violation of the Law of Conservation of Mass?

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Exothermic reactions do not violate the law of conservation of mass, as this principle is more of a guideline than an absolute law. In chemical reactions, the energy changes are minimal compared to the mass of the reactants, making mass conservation appear valid. The concept of mass-energy equivalence is more pronounced in nuclear reactions, where significant mass deficits can be observed. Ultimately, it is the total energy that remains conserved in all reactions, including exothermic ones.
Nikhil faraday
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Are exothermic reactions violation of law of conservation of mass , because energy and mass are equivalent? Please clarify!
 
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Conservation of mass is a rule of thumb, not a fundamental law. It works because the energy gain or loss in chemical reactions is very small compared with the total mass of the reactants. The mass deficit gets obvious in nuclear reactions. It is total energy that gets conserved.

[edit]Note: the mass-energy gain or loss in chemical reactions is very small (order parts per billion) compared with the electro-magnetic energy energy change from just rearranging the atoms.
 
Last edited:
Simon Bridge said:
Conservation of mass is a rule of thumb, not a fundamental law. It works because the energy gain or loss in chemical reactions is very small compared with the total mass of the reactants. The mass deficit gets obvious in nuclear reactions. It is total energy that gets conserved.
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