kekule formula
Very lowTechnical / Academic
Definition
Meaning
A structural formula for a chemical compound, particularly benzene (C₆H₆), in which the carbon atoms form a ring with alternating single and double bonds, as first proposed by August Kekulé.
The term can refer to the specific hexagonal ring structure of benzene, or more broadly to the concept of representing cyclic, conjugated systems with alternating single and double bonds in organic chemistry diagrams.
Linguistics
Semantic Notes
The term is highly specialised and almost exclusively used in the context of organic chemistry and chemical history. It names a specific historical model, which, while foundational, has been largely superseded by the concept of delocalised electrons and resonance structures. It is a proper noun (capitalised) referring to Kekulé's specific hypothesis.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or grammatical differences. The diacritic (é) is often omitted in common usage in both varieties, but is technically part of the correct spelling. Pronunciation may differ based on local conventions for the name 'Kekulé'.
Connotations
Identical. Connotes foundational chemical theory, historical discovery, and a simplified (though still useful) representation of aromatic systems.
Frequency
Identical. Extremely low frequency outside of chemistry textbooks, lectures, and historical discussions.
Vocabulary
Collocations
Grammar
Valency Patterns
the Kekulé formula for benzenedraw a Kekulé formulaaccording to the Kekulé formularepresented by a Kekulé formulaVocabulary
Synonyms
Neutral
Weak
Vocabulary
Antonyms
Usage
Context Usage
Business
Not used.
Academic
Used in chemistry lectures, textbooks, and papers discussing the history of organic chemistry or the structure of aromatic compounds.
Everyday
Not used.
Technical
Core term in organic chemistry for a specific historical and teaching model of cyclic conjugated systems.
Examples
By Part of Speech
adjective
British English
- The Kekulé-type representation is useful for beginners.
American English
- We discussed the Kekulé-type representation in class.
Examples
By CEFR Level
- The classic representation of benzene is known as the Kekulé formula.
- According to the Kekulé formula, benzene has alternating single and double bonds.
- While the Kekulé formula was a groundbreaking proposal for benzene's structure, modern quantum mechanics explains it more accurately as a resonance hybrid.
- The limitations of the static Kekulé formula in explaining benzene's chemical behaviour led to the development of resonance theory.
Learning
Memory Aids
Mnemonic
Kekulé's formula is Key: Envision a Kite-eating tree (the benzene ring) where six snakes (carbon bonds) bite their own tails in alternating pairs (single/double).
Conceptual Metaphor
A RING OF ALTERNATING SPRINGS (single bonds as loose springs, double bonds as tight springs) representing the oscillating bond model.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating 'formula' as 'формула' in the sense of a mathematical equation. Here it means 'структурная формула' or 'схема'.
- Ensure the pronunciation reflects the German origin (Kek-u-lay) and not a direct Cyrillic transliteration.
Common Mistakes
- Spelling as 'Kekule' without the accent (common but technically incorrect).
- Pronouncing it as 'Kek-yool'.
- Using it to describe non-cyclic or non-aromatic molecules.
- Treating it as a current, accurate model rather than a historical/simplified one.
Practice
Quiz
What does the Kekulé formula primarily describe?
FAQ
Frequently Asked Questions
It is a simplified, historical model. While it correctly predicts the 1:1 carbon-hydrogen ratio and cyclic structure, it inaccurately suggests localized, alternating double bonds. Modern chemistry describes benzene as having a delocalised π-electron cloud, giving all bonds equal length and strength (a resonance hybrid).
Friedrich August Kekulé (1829–1896) was a German organic chemist. He is famous for his theories of chemical structure, including the tetravalency of carbon and, most notably, the ring structure of benzene, which he reportedly conceived in a dream of a snake biting its own tail.
It is used almost exclusively in the context of organic chemistry education and history. It appears in chemistry textbooks, academic papers on chemical history, and lectures to illustrate the evolution of thought regarding aromatic compounds.
Yes, the diacritic is part of the correct spelling of his name. However, in informal or fast writing (e.g., lecture notes), it is often omitted, resulting in the spelling 'Kekule'.