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CAS number 95-86-3
[137-09-7] (dihydrochloride)
PubChem 7266
ChemSpider 6996 YesY
Jmol-3D images Image 1
Image 2
Molecular formula C6H8N2O
Molar mass 124.14 g/mol
Appearance Colorless solid
Melting point 78-80 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Amidol is a colorless crystalline compound with the molecular structure C6H3(NH2)2OH. It is a dihydrogen chloride salt and is used as a photographic developer. It was introduced as a developing agent for photographic papers in 1892. It is unusual amongst developing agents as it works most effectively in slightly acid conditions rather than the strongly alkaline conditions required for most other developers. As amidol ages it changes color to a dark red-brown. Developing dishes and equipment used to prepare amidol solutions are also frequently stained brown, a stain that is very persistent.

Prints developed in amidol are typically a very warm brown-black colour, but overdevelopment can quickly lead to chemical fogging.


  1. ^ Merck Index, 11th Edition, 2961.