Lead(II) nitrate is a colourless inorganic compound with the chemical formula Pb(NO3)2. Unlike most other lead(II) salts, it is soluble in water. The use of lead nitrate as a white pigment in paint has been discontinued due to concerns regarding its toxicity.
3D model (JSmol)
|Molar mass||331.2 g/mol|
|Density||4.53 g/cm3 (20 °C)|
|Melting point||470 °C (878 °F; 743 K) decomposes|
|See data page|
Refractive index (nD)
|Face-centred cubic, cP36|
|Pa3, No. 205|
a = 0.78586 nm
Lattice volume (V)
Formula units (Z)
|Safety data sheet||See: data page|
|Lethal dose or concentration (LD, LC):|
LDLo (lowest published)
|500 mg/kg (guinea pig, oral)|
|Supplementary data page|
|Refractive index (n),|
Dielectric constant (εr), etc.
|UV, IR, NMR, MS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
In 1597, the German alchemist Andreas Libavius first described the compound, coining the medieval names of plumb dulcis and calx plumb dulcis, meaning "sweet lead", because of its taste. The production of lead(II) nitrate from either metallic lead or lead oxide in nitric acid was small-scale, for direct use in making other lead compounds. It was produced as a raw material for the production of coloured pigments in lead paints, such as chrome yellow (lead(II) chromate), chrome orange (lead(II) hydroxide chromate) and similar lead compounds. These pigments were used for dyeing and printing calico and other textiles. Although originally not understood during the following centuries, the decrepitation property of lead(II) nitrate led to its use in matches and special explosives.
In the 19th century lead(II) nitrate began to be produced commercially. The production process is chemically straightforward: metallic lead is dissolved in nitric acid. The compound is obtained by crystallization from concentrated solution. The main use was as a white pigment in paint, but the use of lead paint has been superseded by the use of less toxic paints that use titanium dioxide as the white pigment.
Preparation and propertiesEdit
- PbO + 2 HNO3 → Pb(NO3)2 + H2O
The compound crystallizes in the face-centred cubic system, space group Pa3Z=4 (Bravais lattice notation), with unit cell length 784 pm. There is no evidence for free internal rotation of the nitrate groups within the crystal lattice at elevated temperatures.
In nitric acid treatment of lead-containing wastes, e.g., in the processing of lead–bismuth wastes from lead refineries, impure solutions of lead(II) nitrate are formed as by-product. These solutions are reported to be used in the gold cyanidation process.
When concentrated sodium hydroxide solution is added to a nitrate solution, basic nitrates may be formed. Up through the half equivalence point, Pb(NO3)2·Pb(OH)2 predominates, then after this point Pb(NO3)2·5Pb(OH)2 is formed. Simple Pb(OH)2 is not formed up to at least pH 12.
Lead(II) has a standard reduction potential (E0) of −0.125 V and the nitrate ion has an E0 of +0.956 V. These properties show that lead(II) nitrate can behave as an oxidizing agent only towards easily oxidized substrates.
- 2 Pb(NO3)2 (s) → 2 PbO (s) + 4 NO2 (g) + O2 (g)
Lead nitrate has been used to make complexes involving lead(II) because of its relatively high solubility, compared to other lead salts, in various solvents. For example, combining lead nitrate and pentaethylene glycol (EO5) in a solution of acetonitrile and methanol followed by slow evaporation produces the complex [Pb(NO3)2(EO5)]. In the crystal structure for this compound, the EO5 chain is wrapped around the lead ion in an equatorial plane. The two nitrate ligands are both bidentate; one is situated above the plane and the other below. The total coordination number is 10. Reaction of the tripodal ligand 2,4,6-tris[4-(imidazol-1-ylmethyl)phenyl]-1,3,5-triazine (timpt) with lead(II) nitrate produced a polycatenated structure in which the lead atom has a stereochemically active lone pair of electrons. The nitrate ion acts as a bridging ligand in this complex.
Because of the toxicity of lead(II) salts, the production lead paints has all but ceased. Titanium dioxide is now the preferred substance to use as a white pigment in paint. Other historical applications of lead(II) nitrate, such as in matches and fireworks, have declined or ceased as well.
Current applications of lead(II) nitrate include use as a heat stabilization in nylon and polyesters, in thermographic printing paper, and in rodenticides. To improve the leaching process in the gold cyanidation process, lead(II) nitrate solution is added. Although a bulk process, only limited amounts (10 to 100 milligrams lead(II) nitrate per kilogram gold) are required. Both the cyanidation itself, as well as the use of lead compounds in the process, are deemed controversial due to the compounds' toxic nature.
On a laboratory scale, lead(II) nitrate may be used to make nitrogen dioxide. The dry compound is heated in a steel vessel, producing nitrogen dioxide gas, which dimerizes to dinitrogen tetroxide when condensed to a liquid or when it is dissolved in an organic solvent.
- Pb(NO3)2 → PbO2 + 2 NO2
In organic chemistry, lead(II) nitrate has been used as an oxidant, for example as an alternative to the Sommelet reaction for oxidation of benzylic halides to aldehydes. It has also found use in the preparation of isothiocyanates from dithiocarbamates. Because of its toxicity it has largely fallen out of favour, but it still finds occasional use, for example as a bromide scavenger during SN1 substitution.
Lead(II) nitrate is toxic. It must be handled and stored with the appropriate safety precautions to prevent inhalation, ingestion and skin contact. Due to its hazardous nature, the limited applications of lead(II) nitrate are under constant scrutiny.
Ingestion of lead(II) nitrate will lead to acute lead poisoning. All inorganic lead compounds are classified by the International Agency for Research on Cancer (IARC) as probably carcinogenic to humans (Category 2A). They have been linked to renal cancer and glioma in experimental animals and to renal cancer, brain cancer and lung cancer in humans, although studies of workers exposed to lead are often complicated by concurrent exposure to arsenic. Lead is known to substitute for zinc in a number of enzymes, including δ-aminolevulinic acid dehydratase (porphobilinogen synthase) in the haem biosynthetic pathway and pyrimidine-5′-nucleotidase, important for the correct metabolism of DNA and can therefore cause fetal damage.
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