dalton's law
C2Academic/Technical/Scientific
Definition
Meaning
A physical law stating that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
A fundamental principle in chemistry and physics describing the additive nature of pressures in gas mixtures, foundational to understanding gas behavior, partial pressures, and gas-phase reactions. Also known as the law of partial pressures.
Linguistics
Semantic Notes
Refers specifically to John Dalton's 1801 formulation. It assumes ideal gas behavior and non-interacting gases. It is distinct from other 'Dalton's laws' (e.g., Dalton's law of multiple proportions).
Dialectal Variation
British vs American Usage
Differences
No significant difference in usage or spelling. The possessive form 'Dalton's' is universal.
Connotations
Same technical, precise, and historical scientific connotation in both variants.
Frequency
Used with identical frequency in UK and US scientific/engineering discourse.
Vocabulary
Collocations
Grammar
Valency Patterns
Dalton's law [states/implies/means] (that) SENTENCEAccording to Dalton's law, ...One can apply Dalton's law to NPThe calculation is based on Dalton's law.Vocabulary
Synonyms
Neutral
Weak
Usage
Context Usage
Business
Extremely rare. Only in highly specialized contexts like industrial gas engineering or chemical plant safety reports.
Academic
Core terminology in undergraduate chemistry, physics, and chemical engineering courses. Found in textbooks and exam questions.
Everyday
Virtually never used. A purely scientific term.
Technical
Essential in scientific research, gas analysis, thermodynamics, and process engineering for calculating mixture compositions and pressures.
Examples
By CEFR Level
- In simple terms, Dalton's law means each gas in a mix pushes independently.
- To find the pressure of oxygen in air, you can use Dalton's law and its known percentage.
- Dalton's law allows us to calculate the partial pressure of any gas if we know its mole fraction.
- While the ideal gas law describes a pure substance, Dalton's law extends this concept to mixtures of non-interacting gases.
- The experimental validation of Dalton's law becomes more complex under high-pressure conditions where gas interactions are significant.
Learning
Memory Aids
Mnemonic
**D**ifferent gases **A**dd their **L**ittle pressures **T**o make the **O**verall **N**umber – **S**um it up! (DALTON-S).
Conceptual Metaphor
PRESSURE IS A CONTRIBUTION (Each gas contributes its 'share' of pressure to the total, like individuals contributing to a group effort).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid direct translation like "закон Далтона" without specifying it's about partial pressures, as other Dalton's laws exist. Ensure the context is clear.
- Do not confuse 'partial pressure' (парциальное давление) with just 'pressure' (давление). The 'partial' is crucial.
Common Mistakes
- Applying it to reacting gases (it's for non-reacting mixtures).
- Forgetting that it requires the gases to be at the same temperature and volume.
- Confusing it with the ideal gas law (PV=nRT).
- Misspelling as 'Dalton's Law' without the possessive 's'.
Practice
Quiz
Dalton's law is applicable under which condition?
FAQ
Frequently Asked Questions
No. The ideal gas law (PV=nRT) describes the behavior of a single gas. Dalton's law specifically deals with the additive pressures of multiple gases in a mixture.
It is an idealization. For real gases at moderate pressures and temperatures, it is a very good approximation. At high pressures, deviations occur due to intermolecular forces.
The partial pressure of a gas in a mixture is the pressure that gas would exert if it alone occupied the entire volume of the mixture at the same temperature.
John Dalton (1766-1844) was an English chemist, physicist, and meteorologist, best known for pioneering work in atomic theory and his studies of gases, leading to this law and the law of multiple proportions.