Silver sulfate

Silver sulfate

Names
IUPAC name Silver(I) sulfate
Other names Disilver sulfate Argentous sulfate
Identifiers
CAS Number	10294-26-5 Y
3D model (JSmol)	Interactive image
ChemSpider	140554 Y
ECHA InfoCard	100.030.581
EC Number	233-653-7
PubChem CID	159865
UNII	8QG6HV4ZPO Y
UN number	3077
CompTox Dashboard (EPA)	DTXSID70172884
InChI InChI=1S/2Ag.H2O4S/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 Y Key: YPNVIBVEFVRZPJ-UHFFFAOYSA-L Y InChI=1/2Ag.H2O4S/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 Key: YPNVIBVEFVRZPJ-NUQVWONBAA
SMILES [Ag+].[Ag+].[O-]S([O-])(=O)=O
Properties
Chemical formula	Ag2SO4
Molar mass	311.79 g·mol−1
Appearance	Colorless solid
Odor	Odorless
Density	5.45 g/cm3 (25 °C) 4.84 g/cm3 (660 °C)[1]
Melting point	652.2–660 °C (1,206.0–1,220.0 °F; 925.4–933.1 K)[1][5]
Boiling point	1,085 °C (1,985 °F; 1,358 K)[3][5] decomposition
Solubility in water	0.57 g/100 mL (0 °C) 0.69 g/100 mL (10 °C) 0.83 g/100 mL (25 °C) 0.96 g/100 mL (40 °C) 1.33 g/100 mL (100 °C)[2]
Solubility product (Ksp)	1.2·10−5[1]
Solubility	Dissolves in aq. acids, alcohols, acetone, ether, acetates, amides[2] Insoluble in ethanol[3]
Solubility in sulfuric acid	8.4498 g/L (0.1 molH2SO4/LH2O)[2] 25.44 g/100 g (13 °C) 31.56 g/100 g (24.5 °C) 127.01 g/100 g (96 °C)[3]
Solubility in ethanol	7.109 g/L (0.5 nEtOH/H2O)[2]
Solubility in acetic acid	7.857 g/L (0.5 nAcOH/H2O)[2]
Magnetic susceptibility (χ)	−9.29·10−5 cm3/mol[1]
Refractive index (nD)	nα = 1.756 nβ = 1.775 nγ = 1.782[4]
Structure
Crystal structure	Orthorhombic, oF56[4]
Space group	Fddd, No. 70[4]
Point group	2/m 2/m 2/m[4]
Lattice constant	a = 10.2699(5) Å, b = 12.7069(7) Å, c = 5.8181(3) Å[4] α = 90°, β = 90°, γ = 90°
Thermochemistry
Heat capacity (C)	131.4 J/mol·K[1]
Std molar entropy (S⦵298)	200.4 J/mol·K [1]
Std enthalpy of formation (ΔfH⦵298)	−715.9 kJ/mol[1]
Gibbs free energy (ΔfG⦵)	−618.4 kJ/mol [1]
Hazards
GHS labelling:
Pictograms	[6]
Signal word	Danger
Hazard statements	H318, H410[6]
Precautionary statements	P273, P280, P305+P351+P338, P501[6]
NFPA 704 (fire diamond)	[5] 2 0 1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Silver sulfate is the inorganic compound with the formula Ag₂SO₄. It is a white solid with low solubility in water.

Preparation and structure

Silver sulfate precipitates as a solid when an aqueous solution of silver nitrate is treated with sulfuric acid:

2 AgNO₃ + H₂SO₄ → Ag₂SO₄ + 2 HNO₃

It is purified by recrystallization from concentrated sulfuric acid, a step that expels traces of nitrate.^[7] Silver sulfate and anhydrous sodium sulfate adopt the same structure.^[8]

Silver(II) sulfate

The synthesis of silver(II) sulfate (AgSO₄) with a divalent silver ion instead of a monovalent silver ion was first reported in 2010^[9] by adding sulfuric acid to silver(II) fluoride (HF escapes). It is a black solid that decomposes exothermically at 120 °C with evolution of oxygen and the formation of the pyrosulfate.

AgF₂ + H₂SO₄ → AgSO₄ + 2 HF

4 AgSO₄ → 2 Ag₂S₂O₇ + O₂

References