heat of sublimation
LowTechnical
Definition
Meaning
The amount of energy required to change one mole of a substance from solid to gas at a constant temperature and pressure.
The enthalpy change (ΔH) associated with the endothermic physical transition where a solid becomes a gas without passing through a liquid phase. In physics and chemistry, it represents the strength of intermolecular forces in the solid state.
Linguistics
Semantic Notes
The term is a fixed compound noun used primarily in thermodynamics and physical chemistry. Its meaning is precise and quantitative, not figurative. 'Heat' here refers specifically to enthalpy change, and 'sublimation' refers only to the solid-to-gas phase transition.
Dialectal Variation
British vs American Usage
Differences
No differences in usage, spelling, or meaning. It is a standardised international scientific term.
Connotations
None beyond its technical definition.
Frequency
Used with equal and low frequency in both varieties, exclusively within scientific discourse.
Vocabulary
Collocations
Grammar
Valency Patterns
The heat of sublimation of X is...To calculate the heat of sublimationX has a high heat of sublimationVocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Not used.
Academic
Used in university-level chemistry, physics, and materials science courses and research.
Everyday
Virtually never used.
Technical
Primary domain of use. Found in thermodynamics textbooks, research papers, and lab reports.
Examples
By Part of Speech
verb
British English
- Scientists aim to measure how much energy is required to sublime the compound.
American English
- Researchers needed to determine the energy it takes to sublime the material.
adverb
British English
- The solid sublimed rapidly under the vacuum.
American English
- The material sublimed completely, leaving no residue.
adjective
British English
- The sublimation process is highly endothermic for iodine.
Examples
By CEFR Level
- 'Heat of sublimation' is a term used in science.
- The experiment was designed to measure the heat of sublimation of iodine.
- The remarkably high heat of sublimation of diamond is indicative of its extremely strong covalent network structure.
Learning
Memory Aids
Mnemonic
Imagine a solid ice cube turning directly into cold steam (sublimation). The HEAT needed for that direct 'SKIP' (solid→gas) is the heat of sublimation.
Conceptual Metaphor
ENERGY IS A RESOURCE REQUIRED FOR TRANSFORMATION.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse 'heat of sublimation' (теплота сублимации) with 'heat of vaporization' (теплота парообразования) or 'heat of fusion' (теплота плавления). The process is distinct.
Common Mistakes
- Using it to describe the reverse process (deposition).
- Confusing it with melting or boiling.
- Incorrectly assuming it can be used in non-scientific contexts.
Practice
Quiz
What does 'heat of sublimation' specifically measure?
FAQ
Frequently Asked Questions
Yes, it is always positive (endothermic) because energy must be absorbed to overcome the strong intermolecular forces in a solid and form a gas.
It is often difficult to measure directly. It is commonly calculated using Hess's Law as the sum of the heat of fusion and the heat of vaporization.
It is typically expressed in kilojoules per mole (kJ/mol) or sometimes calories per mole (cal/mol).
Very rarely. It might appear in specialised fields like materials science, geology (regarding volatile compounds), or astrophysics (regarding ice in space), but its use remains highly technical.