NTA Abhyas NEET2020Chemistryp Block Elements (Group 15, 16, 17 & 18)Practice
Sodium thiosulphate, N a 2 S 2 O 3 . 5 H 2 O is used in photography to:
Options
- Areduce the silver bromide grains to metallic silver
- Bconvert the metallic silver to silver salt
- Cremove undecomposed AgBr as soluble silver thiosulphate complex
- Dremove reduced silver
Correct answer
C. remove undecomposed AgBr as soluble silver thiosulphate complex
Step-by-step solution
Na 2 S 2 O 3 + AgBr unexposed → Na 3 Ag ( S 2 O 3 ) 2 + NaBr The property is used for fixing in photography.