sesquioxide: meaning, definition, pronunciation and examples
C2 (Proficiency)Scientific/Technical
Quick answer
What does “sesquioxide” mean?
A chemical oxide containing three atoms of oxygen combined with two atoms of another element.
Audio
Pronunciation
Definition
Meaning and Definition
A chemical oxide containing three atoms of oxygen combined with two atoms of another element.
A term from inorganic chemistry for oxides with a formula often written as M₂O₃, indicating a specific 3:2 ratio of oxygen to another element. The prefix 'sesqui-' means 'one and a half', referencing the 1.5:1 ratio of oxygen to the other element.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning or use. It is a standard international scientific term. Spelling conventions follow local norms (e.g., 'analyse' in UK contexts vs. 'analyze' in US when used in surrounding text).
Connotations
None beyond its technical definition.
Frequency
Extremely rare in general language, used exclusively in chemistry, materials science, and geology. Frequency is identical in both UK and US academic/professional contexts.
Grammar
How to Use “sesquioxide” in a Sentence
[Element] sesquioxidesesquioxide of [Element]Vocabulary
Collocations
Examples
Examples of “sesquioxide” in a Sentence
verb
British English
- The compound will sesquioxidise under those conditions. (Rare/technical)
American English
- The metal sesquioxidizes at high temperatures. (Rare/technical)
adverb
British English
- No standard adverbial form exists.
American English
- No standard adverbial form exists.
adjective
British English
- The sesquioxide form of the element was isolated.
American English
- Sesquioxide compounds are common among the lanthanides.
Usage
Meaning in Context
Business
Virtually never used. Might appear in technical reports for chemical or materials industries.
Academic
Exclusively used in chemistry, chemical engineering, materials science, and geology papers and textbooks.
Everyday
Never used.
Technical
The primary and only register. Used to specify oxide compounds with precise stoichiometry.
Watch out
Common Mistakes When Using “sesquioxide”
- Mispronouncing 'sesqui' as /ˈsɛskwi/ instead of /ˌsɛskwɪ/ or /ˌsɛskwi/.
- Incorrectly assuming it refers to any oxide with a 'strange' ratio.
- Misspelling as 'sequioxide'.
- Using it in non-scientific contexts.
FAQ
Frequently Asked Questions
No, it is a highly specialized term used almost exclusively in chemistry and related scientific fields.
Aluminium oxide (Al₂O₃), also known as alumina, is a common and industrially important sesquioxide.
Very rarely. The process might be described as 'forming a sesquioxide' or 'sesquioxidizing', but this is extremely technical jargon.
The ratio of oxygen to the other element is 3:2, which is equivalent to 1.5:1. For every 1 atom of the element (e.g., iron), there are 1.5 atoms of oxygen on average in the compound's formula.
A chemical oxide containing three atoms of oxygen combined with two atoms of another element.
Sesquioxide is usually scientific/technical in register.
Sesquioxide: in British English it is pronounced /ˌsɛskwɪˈɒksʌɪd/, and in American English it is pronounced /ˌsɛskwiˈɑkˌsaɪd/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “No idioms exist for this term.”
Learning
Memory Aids
Mnemonic
Think: 'SESQUI' sounds like 'S (for Six) EQUAL parts?' – but it's one-and-a-half (sesqui). Imagine ONE oxygen atom (O) and a HALF of another element's atom (like .5 of Fe) making a pair? Actually, it's simpler: For every TWO metal atoms, there are THREE oxygen atoms (2:3 ratio). Remember 'SESQUI-CAR' (a carriage with one and a half seats?) leading to an OXIDE.
Conceptual Metaphor
N/A. The term is purely descriptive and mathematical (a ratio).
Practice
Quiz
What does the prefix 'sesqui-' in 'sesquioxide' indicate?