Skip to main content
law of equivalent proportions

law of equivalent proportions

8.1
When two elements each combine with the same third element, they combine with each other in the same amounts
  • noun
  • /lɔː əv ɪˈkwɪvələnt pəˈrɔːpɔrʌn/
  • Specialized
translation icon : ley de proporciones equivalentes
  • According to the law of equivalent proportions, the ratio in which two elements combine with a third will also apply when those two combine with each other.

Examples

  • Dalton cited the law of equivalent proportions as evidence supporting atomic theory.

  • According to the law of equivalent proportions, elements combine in fixed ratios.

  • The law of equivalent proportions helped chemists understand relationships between elements in the early 19th century.

  • The law of equivalent proportions is fundamental in chemistry.

  • According to the law of equivalent proportions, when two elements react with a third element, their combining ratios will be consistent with the ratios they combine with each other.

  • The law of equivalent proportions illustrates how the proportions of elements remain constant during chemical reactions.

  • Chemists rely on the law of equivalent proportions to predict how elements will combine based on their interactions with a third element.

Synonyms

law of reciprocal proportions
vslaw of equivalent proportions
  • Specialized
9.9

When two elements combine with the same mass of a third, they combine with each other in a simple ratio

asserts the ratios are equal rather than allowing multiple values

Surface Forms

Morphology

law + of + equivalent + proportion

The phrase is compositionally built: 'law' signals a scientific rule, 'equivalent' denotes equality in combining power, and 'proportions' refers to ratios, so together they denote a rule about equal ratios. Although the full technical details are domain-specific, the overall meaning is directly inferable from the constituents by a learner who knows those words.

Etymology

Law of equivalent proportions comes from early chemists who measured how elements mix. They found that when element A and element B each 'combine' with element C in fixed 'ratios', the amounts keep the same proportions when A and B combine, so the law says those mixing ratios will match.