Q. $Na_{2}S_{2}O_{3}.5H_{2}O$ is used in photography to
NTA AbhyasNTA Abhyas 2022
Solution:
$Na_{2}S_{2}O_{3}.5H_{2}O$ is used in photography to remove undecomposed AgBr as a soluble complex as:
$\underset{}{\text{AgBr} + 2 \left(\text{Na}\right)_{2} \left(\text{S}\right)_{2} \left(\text{O}\right)_{3}} \rightarrow \underset{\text{Soluble complex}}{\left(\text{Na}\right)_{3} \left[\right. \text{Ag} \left(\text{S}\right)_{2} \left(\text{O}\right)_{3} \left(\left.\right)_{2}\right]} \, + \text{NaBr}$
Sodium thiosulfate is used by photographers to fix developed negatives and prints; it acts by dissolving the part of the silver salts coated onto film which remain unchanged by exposure to light.
$\underset{}{\text{AgBr} + 2 \left(\text{Na}\right)_{2} \left(\text{S}\right)_{2} \left(\text{O}\right)_{3}} \rightarrow \underset{\text{Soluble complex}}{\left(\text{Na}\right)_{3} \left[\right. \text{Ag} \left(\text{S}\right)_{2} \left(\text{O}\right)_{3} \left(\left.\right)_{2}\right]} \, + \text{NaBr}$
Sodium thiosulfate is used by photographers to fix developed negatives and prints; it acts by dissolving the part of the silver salts coated onto film which remain unchanged by exposure to light.