sulphur trioxide: meaning, definition, pronunciation and examples

Very low
UK/ˌsʌl.fə traɪˈɒk.saɪd/US/ˌsʌl.fər traɪˈɑːk.saɪd/

Technical/scientific

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Quick answer

What does “sulphur trioxide” mean?

The chemical compound SO₃, a highly reactive oxide of sulphur.

Audio

Pronunciation

Definition

Meaning and Definition

The chemical compound SO₃, a highly reactive oxide of sulphur.

A colourless to white crystalline solid that reacts violently with water to form sulphuric acid, used in industrial processes.

Dialectal Variation

British vs American Usage

Differences

British English uses 'sulphur'; American English uses 'sulfur' (spelling only).

Connotations

Identical technical connotations in both varieties.

Frequency

Equally rare in both varieties outside chemical contexts.

Grammar

How to Use “sulphur trioxide” in a Sentence

Sulphur trioxide + verb (reacts/forms/decomposes)Verb + sulphur trioxide (produce/generate/handle)

Vocabulary

Collocations

strong
form sulphur trioxideproduce sulphur trioxidereacts with sulphur trioxidesulphur trioxide gas
medium
exposure to sulphur trioxidehandling sulphur trioxidegeneration of sulphur trioxide
weak
dangerous sulphur trioxideindustrial sulphur trioxidepure sulphur trioxide

Examples

Examples of “sulphur trioxide” in a Sentence

verb

British English

  • The catalyst helps to oxidise sulphur dioxide to sulphur trioxide.
  • We must sulphonate carefully to avoid generating excess sulphur trioxide.

American English

  • The process converts sulfur dioxide into sulfur trioxide.
  • They catalytically oxidize the stream to produce sulfur trioxide.

adverb

British English

  • The reaction proceeded sulphur-trioxide-richly.
  • The gas was released sulphur-trioxide-like into the chamber.

American English

  • The mixture reacted sulfur-trioxide-fast.
  • It decomposed sulfur-trioxide-quickly under heat.

adjective

British English

  • The sulphur trioxide production was halted.
  • A sulphur trioxide vapour cloud formed.

American English

  • The sulfur trioxide concentration was measured.
  • A sulfur trioxide leak was contained.

Usage

Meaning in Context

Business

Rare, only in chemical manufacturing or safety reports.

Academic

Common in chemistry textbooks and research papers.

Everyday

Virtually never used.

Technical

Standard term in chemical engineering and industrial chemistry.

Vocabulary

Synonyms of “sulphur trioxide”

Strong

sulfur trioxide (AmE spelling)

Neutral

SO₃

Weak

sulphuric anhydride

Vocabulary

Antonyms of “sulphur trioxide”

Watch out

Common Mistakes When Using “sulphur trioxide”

  • Misspelling as 'sulphur tri-oxide' (hyphenated).
  • Confusing it with sulphur dioxide (SO₂).
  • Incorrect pronunciation stressing the first syllable of 'trioxide'.

FAQ

Frequently Asked Questions

Yes, it is highly corrosive, reacts violently with water, and its fumes are toxic.

Sulphur trioxide (SO₃) has three oxygen atoms and is a solid, while sulphur dioxide (SO₂) has two oxygen atoms and is a gas.

'Sulphur' is the traditional British English spelling; 'sulfur' is the standard American English spelling and the one preferred by the International Union of Pure and Applied Chemistry (IUPAC).

It is not found free in nature due to its high reactivity, but it is produced on an industrial scale and is a component of atmospheric pollution.

The chemical compound SO₃, a highly reactive oxide of sulphur.

Sulphur trioxide is usually technical/scientific in register.

Sulphur trioxide: in British English it is pronounced /ˌsʌl.fə traɪˈɒk.saɪd/, and in American English it is pronounced /ˌsʌl.fər traɪˈɑːk.saɪd/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

  • None

Learning

Memory Aids

Mnemonic

Think: TRIoxide = THREE oxygen atoms bonded to ONE sulphur atom (S + O₃).

Conceptual Metaphor

Often described as a 'precursor' or 'parent' of sulphuric acid.

Practice

Quiz

Fill in the gap
In the industrial production of sulphuric acid, is first converted to sulphur trioxide.
Multiple Choice

What is the primary industrial use of sulphur trioxide?