critical constants: meaning, definition, pronunciation and examples
C2Academic, Technical, Scientific
Quick answer
What does “critical constants” mean?
Specific, unchanging values that define the state of a substance at its critical point where distinct liquid and gas phases cease to exist.
Audio
Pronunciation
Definition
Meaning and Definition
Specific, unchanging values that define the state of a substance at its critical point where distinct liquid and gas phases cease to exist.
In thermodynamics and physical chemistry, the set of characteristic values (critical temperature, critical pressure, and critical volume) for a pure substance at its critical point, marking the end of the liquid-vapor equilibrium line. In broader technical contexts, the term can be extended to refer to key, fixed parameters that determine a system's behavior at a critical threshold.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling conventions (e.g., 'behaviour' vs. 'behavior') may apply in surrounding text.
Connotations
Identical technical connotation in both varieties.
Frequency
Equally rare and specialised in both UK and US academic/engineering contexts.
Grammar
How to Use “critical constants” in a Sentence
The critical constants {of/for} {substance} are...{Substance} has critical constants of...Based on the critical constants, ...Vocabulary
Collocations
Examples
Examples of “critical constants” in a Sentence
adjective
British English
- The critical constants table is in the appendix.
- We need the critical constants data for methane.
American English
- The critical constants chart is in the appendix.
- We need the critical constants data for propane.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in chemistry, physics, chemical engineering, and thermodynamics textbooks and research papers.
Everyday
Extremely rare; would not be used in casual conversation.
Technical
Essential term in process engineering, supercritical fluid applications, and thermodynamic modelling.
Vocabulary
Synonyms of “critical constants”
Strong
Neutral
Weak
Vocabulary
Antonyms of “critical constants”
Watch out
Common Mistakes When Using “critical constants”
- Using the singular 'constant' (it is nearly always plural).
- Confusing with 'critical *values*' which can be more general.
- Incorrectly using for non-thermodynamic thresholds (e.g., 'the critical constants of the project').
FAQ
Frequently Asked Questions
Typically, yes. The term conventionally refers to the critical temperature (Tc), critical pressure (Pc), and critical volume (Vc) or critical density. Sometimes the critical compressibility factor (Zc) is included as a derived constant.
It is highly unusual and would be considered a metaphorical extension, such as in systems theory to describe key immutable thresholds. Its primary and almost exclusive domain is physical science and engineering.
They are determined experimentally by observing the disappearance of the meniscus between liquid and gas phases in a sealed tube under controlled conditions, or estimated using thermodynamic equations of state and group contribution methods.
The 'critical point' is the singular state (the specific condition) defined by a unique combination of temperature and pressure. The 'critical constants' are the numerical values (temperature, pressure, volume) that characterize that point.
Specific, unchanging values that define the state of a substance at its critical point where distinct liquid and gas phases cease to exist.
Critical constants is usually academic, technical, scientific in register.
Critical constants: in British English it is pronounced /ˈkrɪtɪkəl ˈkɒnstənts/, and in American English it is pronounced /ˈkrɪtɪkəl ˈkɑːnstənts/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “[None - too technical for idiomatic use]”
Learning
Memory Aids
Mnemonic
Imagine a liquid and gas having a CRITICAL meeting. They agree on three CONSTANT rules (temperature, pressure, volume) to become one supercritical fluid.
Conceptual Metaphor
A FINGERPRINT for a substance's phase behavior / The COORDINATES of a phase boundary.
Practice
Quiz
What do 'critical constants' specifically refer to in physical chemistry?