law of definite proportions
- noun
- /lɔː ʌv ˈdɛfɪnɪt prəˈpɔrʃənz/
- Specialized
:
ley de proporciones definidas
- The law of definite proportions states that a chemical compound always contains exactly the same proportion of elements by mass.
Examples
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According to the law of definite proportions, water always contains hydrogen and oxygen.
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Dalton used the law of definite proportions as a foundation for his atomic theory.
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Without the law of definite proportions, chemists could not accurately formulate chemical equations.
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The law of definite proportions is fundamental in chemistry.
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The law of definite proportions states that a chemical compound always contains exactly the same proportion of elements by mass.
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According to the law of definite proportions, water always contains hydrogen and oxygen.
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Dalton used the law of definite proportions as a foundation for his atomic theory.
Synonyms
A rule that a pure material always contains the same elements in the same amounts by weight, for example water
Surface Forms
Morphology
law + of + definite + proportion
The phrase is compositionally built: 'law of X' indicates a rule about X, and 'definite proportions' literally means specific/fixed ratios, so a learner who knows the constituents can infer it is a rule about fixed proportions. The precise technical detail (e.g. elements combining by weight in chemistry) is domain-specific, but the basic meaning is transparently derivable from the parts and follows a common cross-linguistic pattern.
Etymology
Law of definite proportions came from chemists who noticed a pure substance always follows the same 'recipe'—the same elements in the same amounts. The words law, definite, and proportions show this idea of a fixed rule, so the phrase means a compound always contains the same elements in the same amounts by weight.
