Sodium thiosulfate, represented by the chemical formula Na2S2O3, is an inorganic compound commonly used in various applications. It appears as a white crystalline powder and is highly soluble in water. Sodium thiosulfate is often utilized in photography as a fixer to dissolve unexposed silver halides, making it essential in developing photographs. In addition to its role in photography, Na2S2O3 is used in medicine as an antidote for cyanide poisoning. It works by converting cyanide into a less toxic compound that can be excreted by the body. Furthermore, sodium thiosulfate is employed in water treatment processes to neutralize chlorine and in analytical chemistry for titrations.