Union Public Service Commission
Combined Defence Services Exam, 2011
(Held on September 2011)
General Knowledge : Fully Solved
1. Sodium thiosulfate (Na2S2O3) solution is used in photography to –
(A) remove reduced silver
(B) reduce silver bromide (AgBr) grain to silver
(C) remove undecomposed AgBr as a soluble silver thiosulfate complex
(D) convert the metallic silver to silver salt
Ans