A Levels Chemistry

In black and white photographic film, light converts silver chloride into metallic silver. After the film
has been developed, the unreacted silver chloride is removed by reaction with sodium thiosulfate
to produce a 'fixed' negative.
AgCl+ 2Na,S,O3 → 4Na* + Cl- + [Ag(S,O3)2j*
What is the function of the thiosulfate ion?
A to make the silver ions soluble
B to oxidise the silver ions
C to oxidise the silver metal
to reduce the silver ions


Redox - Oxidation Number Calculation | 2009 - M/J - 9701/1 | Q15