critical temperature: meaning, definition, pronunciation and examples
C2Formal, Scientific, Technical
Quick answer
What does “critical temperature” mean?
The specific temperature above which a substance cannot exist as a liquid, no matter how much pressure is applied. It marks the endpoint of the liquid-vapor phase equilibrium line.
Audio
Pronunciation
Definition
Meaning and Definition
The specific temperature above which a substance cannot exist as a liquid, no matter how much pressure is applied. It marks the endpoint of the liquid-vapor phase equilibrium line.
By metaphorical extension, any pivotal temperature at which a material undergoes a fundamental, irreversible change in its physical or chemical properties, often causing a system failure.
Dialectal Variation
British vs American Usage
Differences
No lexical or semantic differences. Spelling of related terms may follow regional conventions (e.g., vapour vs. vapor).
Connotations
Identical technical connotations. In everyday figurative use, it may connote a 'breaking point' or 'failure point' in both varieties.
Frequency
Exclusively used in scientific, engineering, and technical contexts in both varieties. Virtually absent from general conversation.
Grammar
How to Use “critical temperature” in a Sentence
The critical temperature of NOUN is NUMBER.NOUN has a critical temperature of NUMBER.Above its critical temperature, NOUN VERB.Vocabulary
Collocations
Usage
Meaning in Context
Business
Rare. Might be used in high-tech manufacturing or energy sector risk reports: 'Exceeding the critical temperature of the coolant would halt production.'
Academic
Primary context. Used in physics, chemistry, materials science, and engineering papers: 'The experiment aimed to determine the critical temperature of the new superconductor.'
Everyday
Extremely rare. Only in figurative speech by technically-minded individuals: 'My phone hit its critical temperature and shut down.'
Technical
Core context. Central to thermodynamics, HVAC, aerospace, chemical engineering, and superconductivity research.
Vocabulary
Synonyms of “critical temperature”
Neutral
Weak
Vocabulary
Antonyms of “critical temperature”
Watch out
Common Mistakes When Using “critical temperature”
- Using it as a general synonym for 'dangerously high temperature'.
- Confusing it with 'flash point' or 'auto-ignition temperature' in chemistry.
- Treating it as an adjective-noun phrase (e.g., 'a critical temperature') rather than a fixed compound noun with a specific definition.
FAQ
Frequently Asked Questions
No. Boiling point is the temperature at which a liquid turns to vapour at a given pressure (often 1 atm). Critical temperature is the highest temperature at which a distinct liquid phase can exist, regardless of pressure.
Yes. In a pressurised water reactor (PWR), if the coolant water exceeds its critical temperature (374°C), it becomes a supercritical fluid with different properties, which can lead to a loss of cooling ability and a potential reactor accident.
For a superconductor, the critical temperature (Tc) is the temperature below which it exhibits zero electrical resistance. A higher Tc is crucial for practical applications, as it reduces or eliminates the need for expensive cryogenic cooling.
Rarely, and only figuratively. One might say, 'The political situation has reached a critical temperature,' meaning tensions are at a point where a major, irreversible change is imminent. This is metaphorical, not scientific.
The specific temperature above which a substance cannot exist as a liquid, no matter how much pressure is applied. It marks the endpoint of the liquid-vapor phase equilibrium line.
Critical temperature is usually formal, scientific, technical in register.
Critical temperature: in British English it is pronounced /ˌkrɪt.ɪ.kəl ˈtem.prə.tʃər/, and in American English it is pronounced /ˌkrɪt̬.ɪ.kəl ˈtem.pɚ.ə.tʃɚ/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Imagine a CRITICAL patient (critical) whose fever (temperature) is so high that their state changes irreversibly. That fever point is the CRITICAL TEMPERATURE.
Conceptual Metaphor
A POINT OF NO RETURN for physical states; a LIMIT or BOUNDARY between two fundamental realms of existence (liquid vs. gas).
Practice
Quiz
What is the primary defining characteristic of a substance's critical temperature?