Question

The chemical used as a ‘fixer’ in photography is __________.
a.) Sodium sulphate
b.) Sodium thiosulphate
c.) Ammonium persulphate
d.) Potassium sulphate

Answer 1

Hint: To find the appropriate solution of the given question, we need to have a brief with the terminology photographic fixer, which is a mix of chemicals that is used in the final step of the photographic film or paper, in which the film loses its original silver halide milkiness overlaying the original image and becomes clear.

Complete Solution :
The process for which a chemical fixer is used is called Fixation which is generally achieved by treating the photographic film or paper with a solution of thiosulphate salt and Sodium thiosulphate \[\left( N{{a}_{2}}{{S}_{2}}{{O}_{3}} \right)\], is one of the popular salts that are used by photographers to fix developed negatives and prints. It acts by dissolving the part of the silver halide salts coated onto the film which remain unchanged by the exposure to light.
So, the correct answer is “Option B”.

Note: One is advised to look at other incorrect options as well which are:
- Sodium sulphate or specifically anhydrous sodium sulphate is generally used as filler in powdered home laundry detergents dry organic liquids i.e. to dry organic liquids and might be also useful to remove certain acetaminophen from the body as a laxative.
- Ammonium persulphate is a strong inorganic compound highly soluble in water and is generally use as an oxidizing agent that is often used with Tetramethylenediamine to catalyze the polymerization of acrylamide and bisacrylamide to prepare polyacrylamides for electrophoresis.
- Potassium sulphate also known as sulphate of potash is dominantly used as an ingredient in fertilizers though it might be harmful for crops due to its lacking in chloride but is preferred for crops including tobacco and few fruits and vegetables.