ammonium thiosulfate: meaning, definition, pronunciation and examples
RareTechnical/Scientific
Quick answer
What does “ammonium thiosulfate” mean?
An inorganic chemical compound with the formula (NH4)2S2O3, composed of ammonium cations and thiosulfate anions, typically appearing as a white, water-soluble crystalline solid.
Audio
Pronunciation
Definition
Meaning and Definition
An inorganic chemical compound with the formula (NH4)2S2O3, composed of ammonium cations and thiosulfate anions, typically appearing as a white, water-soluble crystalline solid.
A chemical used extensively as a fixing agent (photographic fixer) to remove unexposed silver halides from film and photographic paper. It is also used in gold extraction, in some medical applications as a topical treatment for certain skin conditions (e.g., lichen planus), and as a leaching agent in mining and metallurgy.
Dialectal Variation
British vs American Usage
Differences
Spelling differences follow the general pattern for chemical names. British English may occasionally favour 'thiosulphate', though 'thiosulfate' is widely accepted in scientific contexts. American English consistently uses 'thiosulfate'.
Connotations
Identical. No cultural or connotative differences exist; purely a technical term.
Frequency
Equally rare in both dialects, confined to chemistry, photography, mining, and related technical fields.
Grammar
How to Use “ammonium thiosulfate” in a Sentence
Used as [uncountable noun]: Add ammonium thiosulfate to the tank.Used with [preposition 'in']: It is used in photographic fixing.Used with [preposition 'as']: It functions as a leaching agent.Vocabulary
Collocations
Examples
Examples of “ammonium thiosulfate” in a Sentence
adjective
British English
- The ammonium thiosulfate solution was prepared fresh.
- A standard ammonium thiosulfate fixer was used.
American English
- The ammonium thiosulfate concentrate is highly soluble.
- We need an ammonium thiosulfate-based leaching process.
Usage
Meaning in Context
Business
Rare. May appear in procurement lists for chemical suppliers, mining operations, or photographic equipment companies.
Academic
Common in chemistry, chemical engineering, metallurgy, and photographic science textbooks and research papers.
Everyday
Virtually non-existent. Known only to hobbyist photographers, chemists, or professionals in specific industries.
Technical
Standard term in technical manuals for photography, mining processes, and laboratory chemical procedures.
Vocabulary
Synonyms of “ammonium thiosulfate”
Strong
Neutral
Vocabulary
Antonyms of “ammonium thiosulfate”
Watch out
Common Mistakes When Using “ammonium thiosulfate”
- Misspelling as 'thiosulphate' (though acceptable in BrE).
- Incorrect hyphenation: 'ammonium-thiosulfate'.
- Pronouncing 'thio-' as /θiːoʊ/ instead of /θaɪoʊ/.
FAQ
Frequently Asked Questions
It can be irritating to skin, eyes, and respiratory system. It is not highly toxic like cyanide, but proper safety equipment (gloves, goggles) should be used when handling it.
They are similar chemically but have different cations (ammonium vs. sodium). Ammonium thiosulfate is often a 'rapid fixer' in photography, acting faster than sodium thiosulfate ('hypo').
While it contains nitrogen and sulfur, it is not a standard fertiliser. Its use in agriculture is very limited and specific; it is not recommended for general garden use.
It reacts with the unexposed, light-sensitive silver halide crystals on the film or paper, converting them into soluble complexes that can be washed away, leaving behind the stable metallic silver that forms the image.
An inorganic chemical compound with the formula (NH4)2S2O3, composed of ammonium cations and thiosulfate anions, typically appearing as a white, water-soluble crystalline solid.
Ammonium thiosulfate is usually technical/scientific in register.
Ammonium thiosulfate: in British English it is pronounced /əˌməʊniəm ˌθaɪəʊˈsʌlfeɪt/, and in American English it is pronounced /əˈmoʊniəm ˌθaɪoʊˈsʌlfeɪt/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think: AMMOnia (NH4) teaming up with THIO (sulfur) to SULFATE (a sulfur-oxygen compound) to FIX photos.
Conceptual Metaphor
A SCRUBBER or ERASER (conceptually removes unwanted silver from film). A LEACHER (extracts metals from ore).
Practice
Quiz
What is the primary industrial use of ammonium thiosulfate outside of photography?