Question

What type of reaction is involved in the usage of AgBr in photography ? The positive print developed is dipped in AuCl3 solution at the end to impart a beautiful appearance to the photograph. Explain the reaction involved in this justify.

Answer 1

Acid base reaction takes place in the photography.
Black and white photography brings out details and contrast. The way black and white photographs are created depends on the exposure of light sensitive material which forms the image, in terms of film photography. It starts with silver halides which is the light sensitive material, known as AgBr. AgBr is exposed to form the image depending on the frequency of light which is involved in this process. After being exposed to light, the AgBr forms an image on the film. When developing the image, the exposed AgBr grains convert to visible metallic deposit using an oxidized reducing agent, sodium sulphate.
$2AgBr\to 2Ag+B{r}_2$