7785-23-1 Usage
Chemical Properties
Silver bromide, AgBr, is pale yellow crystals or powder, that darken on exposure to light, finally turning black and soluble in potassium bromide, potassium cyanide, and sodium thiosulfate solutions, only very slightly soluble in ammonia water, insoluble in water, and light sensitive. Derivation is through silver nitrate dissolving in water and a solution ofalkali bromide added slowly. The precipitated silver bromide is washed repeatedly with hotwater. The operation must be carried on in a darkroom under a ruby-red light. Used in photographic film and plates, photochromic glass and as a laboratory reagent.
Physical properties
Yellow cubic crystals or powder; refractive index 2.253; darkens on exposure to light; Mohs hardness 2.5; density 6.47g/cm3; melts at 432°C; vaporizes at 1,502°C; insoluble in water, alcohol, and most acids; slightly soluble in dilute ammonia and ammonium carbonate solutions; sparingly soluble in concentrated ammonia solution (0.33 g/100mL 10% ammonia solution at 12°C);soluble in alkali cyanide solutions.
Uses
Different sources of media describe the Uses of 7785-23-1 differently. You can refer to the following data:
1. Silver Bromide is used in the spectroscopic study of silver halides in montmorillonite and their antibacterial activity, also used in the antimicrobial compositions for use in wound care products.
2. A yellowish powder made by the combination of any soluble
bromide with silver nitrate. Silver bromide could also be
formed by exposing metallic silver to the fumes of bromine
as in the daguerreotype process. It is soluble in sodium thiosulfate,
potassium bromide, and potassium cyanide solutions.
Silver bromides were secondary halides for the paper negative
processes, albumen negative process, and wet or preserved
collodion processes. Silver bromides were the primary halides
for the silver bromide collodion emulsion negative and the
silver bromide gelatin emulsion processes. Silver bromide is
the most photosensitive silver halide.
Preparation
Silver bromide is prepared by double decomposition reaction. An aqueous solution of alkali bromide, such as sodium or potassium bromide, is slowly added to an aqueous solution of silver nitrate:Ag+ (aq) + Brˉ (aq) → AgBr(s)The precipitate is washed repeatedly with hot water. Preparation should be in a dark room under a ruby red light.
Flammability and Explosibility
Nonflammable
Purification Methods
It is insoluble in dilute HNO3 or dilute NH3 but is soluble in conc NH3. Store it in the dark.
Check Digit Verification of cas no
The CAS Registry Mumber 7785-23-1 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,7,8 and 5 respectively; the second part has 2 digits, 2 and 3 respectively.
Calculate Digit Verification of CAS Registry Number 7785-23:
(6*7)+(5*7)+(4*8)+(3*5)+(2*2)+(1*3)=131
131 % 10 = 1
So 7785-23-1 is a valid CAS Registry Number.
InChI:InChI=1/Ag.BrH/h;1H/q+1;/p-1
7785-23-1Relevant articles and documents
Photoelectron spectroscopy of AgCl, AgBr, and AgI vapors
Berkowitz, J.,Batson, C. H.,Goodman, G. L.
, p. 5829 - 5837 (1980)
He I photoelectron spectra of AgCl, AgBr and AgI vapors have been obtained which differ significantly from earlier work.In each instance, the characteristic features of the diatomic molecule are prominent.The spectral features separate into a valence region, predominantly halogen p-like, and a deeper region, predominantly of Ag 4d character.The latter is split by spin-orbit and ligand field interactions, which are parametrized from the experimental data.Relativistic calculations of the Xα-DVM-SCC type have been performed for these species.At the transition statelevel, they agree very well with the experimental peak positions.Nonrelativistic calculations of this type have been performed for CuCl and cyclic Cu3Cl3.Unlike the AgX species, the CuCl and Cu3Cl3 exhibit strong mixing of metal d and halogen p orbitals for the uppermost occupied orbital, and other Cu 3d-like orbitals above the Cl 3p-like orbitals.It is suggested that the occurrence of Cu 3d orbitals in the valence region may play a role in the anomalous diamagnetic signal and large conductivity changes of CuCl condensed from the vapor.
