Sodium thiosulfate, Na₂S₂O₃ ·5H₂O, is used in photography to:
Correct answer: C. Remove undecomposed AgBr as soluble silver thiosulphate complex
- A. Reduce the silver bromide grains to metallic silver
- B. Convert the metallic silver to silver salt
- C. Remove undecomposed AgBr as soluble silver thiosulphate complex
- D. Remove reduced silver
Explanation
In the photographic fixing process, sodium thiosulfate (hypo) is used to remove the unexposed and undeveloped silver bromide (AgBr) from the film. It does this by forming a stable, soluble complex ion, [Ag(S₂O₃)₂]³⁻, which can then be washed away.
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About s-Block and p-Block Elements
The s and p blocks are studied through their valence-shell configurations, periodic trends and characteristic chemical properties. Work covers the reactions of Group I and Group II elements, the behaviour of Group IV elements, and how atomic size, ionization energy, electronegativity and metallic character change across periods and down groups.
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