Sodium thiosulfate photography

Sodiura/polassium ATPase, 555 Sodium pump, 555 mechanism, 556 Sodium salts electrolyte balance, 771 Sodium thiosulfate photography... 

Uses. The principal use for sodium thiosulfate continues to be as fixative in photography (qv) to dissolve undeveloped silver haUde from negatives or prints. In appHcations where rapid processing is requited, such as the processing of x-ray film, sodium thiosulfate has been largely replaced by ammonium thiosulfate. 

Ammonium thiosulfate, (NH 2S2 3 commonly referred to as ammo hypo, has displaced sodium thiosulfate in photography. It is normally sold in the United States only as the aqueous solution. In addition, a crystal slurry and anhydrous crystal are available in Europe. 

The principal use of photochemical-grade ammonium thiosulfate continues to be in photography, where is dissolves undeveloped silver haUdes from negatives and prints. It reacts considerably faster than sodium thiosulfate, and the fixing solutions can be used about twice as long as sodium thiosulfate solutions the washing period to remove residual thiosulfate is shorter. 

Silver halide salts are used in black and white photography. During the developing process, excess silver halide is removed from the film by using a solution of sodium thiosulfate (commonly called hypo ). 

Sodium thiosulfate, NaoS203 5H20 (incorrectly called hypo, from an old name sodium hyposulfite), is a substance used in photography (Chap. 27). It is made by boiling a solution of sodium sulfite with free sulfur ... 

In film photography, sodium thiosulfate (Na2S203)—also known as sodium hyposulfite—is used to stop the developing process. Photo processors refer to it as hypo. 

The compound sodium thiosulfate pentahydrate, Na2S203 5H20, is important commercially to the photography business as "hypo," because it has the ability to dissolve unreacted silver salts from photographic film during development. Sodium thiosulfate pentahydrate can be produced by boiling elemental sulfur in an aqueous solution of sodium sulfite. 

Na2S203 5H2O Sodium thiosulfate pentahydrate Hypo Film photography... 

One way to make sodium thiosulfate, known as hypo and used in photographie developing, is described by the equation Na2COj + 2 NajS + 4 SOj 3 Na2S203 + CO2. How many grams of sodium carbonate are required to produce 681 grams of sodium thiosulfate ... 

The use of sodium thiosulfate as the hypo in black-and-white photography is described in Chapter 6 (p. 132). It is also a moderately strong reducing agent and is routinely used to determine the amount of iodine produced in various quantitative analytical procedures generally referred to as iodimetry. The reaction of thiosulfate with iodine is shown in Equation (17.18) ... 

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