Question

Sodium thiosulphate is used in photography.

• A. To convert metallic silver into silver salt
• B. AgBr grain is reduced to non-metallic silver
• C. To remove reduced silver
• D. To remove undecomposed AgBr in the form of $Na_{3}\lbrack Ag\lbrack S_{2}O_{3})_{2}\rbrack$ (a complex salt)

Answer 1

Answer: (A)

To convert metallic silver into silver salt

Answer 2

Sodium thiosulphate is a reducing agent which convert metalic silver into silver salt.