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General Chemistry

Law of Conservation of Matter

Definition and meaning of Law of Conservation of Matter in chemistry.

The Law of Conservation of Matter states that matter cannot be created or destroyed in an isolated system during an ordinary chemical reaction or physical change. It asserts that the total mass of the reactants must perfectly equal the total mass of the products.

In more detail

This fundamental scientific principle was established by Antoine Lavoisier in the late eighteenth century. In any closed system, atoms are merely rearranged to form new compounds, but the total number of each type of atom remains constant throughout the process. This law forms the essential basis for balancing chemical equations and performing quantitative stoichiometric calculations. While nuclear reactions can convert matter directly into energy, the law holds true for all standard chemical processes.

Key facts

FieldGeneral Chemistry
DiscovererAntoine Lavoisier
ApplicationBalancing chemical equations
Example

When 12 grams of solid carbon react completely with 32 grams of oxygen gas, exactly 44 grams of carbon dioxide gas are produced, demonstrating that total mass is perfectly conserved.

Frequently asked questions

Does the Law of Conservation of Matter apply to nuclear reactions?

No, in nuclear reactions, significant amounts of mass are converted directly into energy according to Einstein's mass-energy equivalence principle.

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