Skip to main content
Glite Dictionary
law of constant proportion

law of constant proportion

6.0
A rule that a pure material always contains the same elements in the same amounts by weight, for example water
  • noun
  • Specialized
translation icon : ley de proporciones constantes
  • The law of constant proportion explains why water always contains hydrogen and oxygen in a fixed ratio by mass.

Examples

  • In chemistry class, we learned how the law of constant proportion applies to the formation of compounds like carbon dioxide.

  • Thanks to the law of constant proportion, scientists can predict the composition of pure substances.

  • The law of constant proportion applies to all chemical compounds.

  • Did you learn about the law of constant proportion in chemistry class?

  • In chemistry, the law of constant proportion states that every pure substance always has the same elements in fixed weight ratios.

  • According to the law of constant proportion, the ratio of elements in a compound is always consistent, allowing for accurate predictions in chemical reactions.

  • The law of constant proportion demonstrates that water, regardless of its source, is always composed of two hydrogen atoms for every one oxygen atom.

Synonyms

law of definite proportions
vslaw of constant proportion
  • Specialized
6.1

A pure substance always contains the same elements in the same amounts by weight

has identical meaning but uses an alternative traditional name

Surface Forms

law of constant proportion singular
laws of constant proportion plural

Morphology

law + of + constant + proportion

The phrase literally combines 'law' (a rule), 'constant' (not varying) and 'proportion' (relationship of parts), so its meaning — a rule that certain proportions remain unchanged — is directly derivable from the constituents. This follows standard scientific naming patterns (e.g. 'law of X') and is cross-linguistically transparent, so a B1 learner who knows the component words can infer the intended meaning.

Etymology

Law of constant proportion comes from a simple idea: think of a chemical as a fixed recipe, where the word law is a 'rule', constant means it does not change, and proportion is the amount of each part. That's why the phrase means a 'rule' that a pure substance always has the same elements in the same amounts.