Silver nitrate

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Silver nitrate
Silver nitrate by NileRed.jpg
Dry silver nitrate crystals
Names
IUPAC name
Silver nitrate
Preferred IUPAC name
Silver nitrate
Systematic IUPAC name
Silver nitrate
Other names
Argenti nitras
Lunar caustic
Nitric acid silver(I) salt
Silver(I) nitrate
Properties
AgNO3
Molar mass 169.87 g/mol
Appearance White solid
Odor Odorless
Density 4.35 g/cm3 (24 °C)
3.97 g/cm3 (210 °C)
Melting point 209.7 °C (409.5 °F; 482.8 K)
Boiling point 440 °C (824 °F; 713 K) (decomposes)
122 g/100 ml (0 °C)
170 g/100 ml (10 °C)
256 g/100 ml (25 °C)
373 g/100 ml (40 °C)
912 g/100 ml (100 °C)
Solubility Soluble in ammonia, diethyl ether, glycerol
Solubility in acetic acid 0.0776 g/100 g (30 °C)
0.1244 g/100 g (40 °C)
0.5503 g/100 g (93 °C)
Solubility in acetone 0.35 g/100 g (14 °C)
0.44 g/100 g (18 °C)
Solubility in benzene 0.022 g/100 g (35 °C)
0.044 g/100 g (40.5 °C)
Solubility in ethanol 3.1 g/100 g (19 °C)
Solubility in ethyl acetate 2.7 g/100 g (20 °C)
Vapor pressure ~0 mmHg
Viscosity 3.77 cP (244 °C)
3.04 cP (275 °C)
Thermochemistry
140.9 J·mol-1·K-1
−124.4 kJ/mol
Hazards
Safety data sheet FisherScientific
Flash point Non-flammable
Related compounds
Related compounds
Silver sulfate
Silver perchlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Silver nitrate is a chemical compound, salt of nitric acid and silver metal. It has the chemical formula AgNO3.

Properties

Chemical

Silver nitrate can be reduced to elemental silver, in the presence of a reducing agent, such as ascorbic acid.

Silver nitrate decomposes when heated at 440 °C.

2 AgNO3 → 2 Ag + O2 + 2 NO2(g)

Physical

Silver nitrate is an odorless white salt (older samples may appear gray). Unlike silver perchlorate, it is not hygroscopic. It is soluble in water, acetone, ether.

Availability

Silver nitrate can be purchased from pharmacies, usually as a solution or as sticks, known as "caustic pencils". In some countries, these pencils contain a mixture of silver and potassium nitrates, and purification is required.

It can also be purchased in solid form, from chemical suppliers.

Preparation

Silver nitrate can be prepared by reacting nitric acid with silver metal.

3 Ag + 4 HNO3 (cold and diluted) → 3 AgNO3 + 2 H2O + NO
Ag + 2 HNO3 (hot and concentrated) → AgNO3 + H2O + NO2

Heating the acid accelerates the reaction. The reaction produces lots of nitrogen dioxide.

Projects

Handling

Safety

Silver nitrate can stain the skin as well as most objects and is toxic if swallowed. Protection gloves should be worn when handling the compound.

Contact with ethanol may cause explosion.

Storage

Silver nitrate should be kept in closed bottles, in dark places, such as a cabinet, as it is sensitive to light. Avoid storing it close to volatile reducing agents.

Disposal

Silver nitrate should be reduced to elemental silver, which can be recycled.

References

Relevant Sciencemadness threads