Lead(II) nitrate is an
inorganic compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemis ...
with the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
Pb(
NO3)
2. It commonly occurs as a colourless
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macro ...
or white powder and, unlike most other lead(II)
salts, is
soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solubi ...
in
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...
.
Known since the
Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire ...
by the name plumbum dulce, the production of lead(II) nitrate from either metallic
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...
or
lead oxide in
nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available ni ...
was small-scale, for direct use in making other
lead compounds
Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions.
Chemistry
Various oxidized forms of ...
. In the nineteenth century lead(II) nitrate began to be produced commercially in Europe and the United States. Historically, the main use was as a raw material in the production of
pigment
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...
s for
lead paint
Lead paint or lead-based paint is paint containing lead. As pigment, lead(II) chromate (, "chrome yellow"), lead(II,IV) oxide, (, "red lead"), and lead(II) carbonate (, "white lead") are the most common forms.. Lead is added to paint to acce ...
s, but such paints have been superseded by less toxic paints based on
titanium dioxide
Titanium dioxide, also known as titanium(IV) oxide or titania , is the inorganic compound with the chemical formula . When used as a pigment, it is called titanium white, Pigment White 6 (PW6), or CI 77891. It is a white solid that is insolu ...
. Other industrial uses included heat
stabilization in
nylon
Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic.
Nylon is a silk-like thermoplastic, generally made from pet ...
and
polyester
Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include natura ...
s, and in coatings of
photothermographic paper. Since around the year 2000, lead(II) nitrate has begun to be used in
gold cyanidation.
Lead(II) nitrate is
toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a sub ...
and must be handled with care to prevent inhalation, ingestion and skin contact. Due to its
hazardous nature, the limited applications of lead(II) nitrate are under constant scrutiny.
History
Lead nitrate was first identified in 1597 by the
alchemist
Alchemy (from Arabic: ''al-kīmiyā''; from Ancient Greek: χυμεία, ''khumeía'') is an ancient branch of natural philosophy, a philosophical and protoscientific tradition that was historically practiced in China, India, the Muslim ...
Andreas Libavius, who called the substance ''plumbum dulce'', meaning "sweet lead", because of its taste.
It is produced commercially by reaction of metallic
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...
with concentrated
nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available ni ...
in which it is sparingly soluble.
It has been produced as a raw material for making pigments such as
chrome yellow (lead(II) chromate, PbCrO
4) and
chrome orange (basic lead(II) chromate, Pb
2CrO
5) and
Naples yellow. These pigments were used for
dyeing
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular c ...
and printing
calico and other textiles.
It has been used as an oxidizer in
black powder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). T ...
and together with
lead azide
Lead(II) azide is an inorganic compound. More so than other azides, is explosive. It is used in detonators to initiate secondary explosives. In a commercially usable form, it is a white to buff powder.
Preparation and handling
Lead(II) azide i ...
in special
explosives
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...
.
Production
Lead nitrate is produced by reaction of
lead(II) oxide
Lead(II) oxide, also called lead monoxide, is the inorganic compound with the molecular formula Pb O. PbO occurs in two polymorphs: litharge having a tetragonal crystal structure, and massicot having an orthorhombic crystal structure. Modern ap ...
with concentrated nitric acid:
: PbO + 2 HNO
3(concentrated) → Pb(NO
3)
2↓ + H
2O
It may also be obtained evaporation of the solution obtained by reacting
metallic lead with dilute
nitric acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available ni ...
.
: Pb + 4 HNO
3 → Pb(NO
3)
2 + 2 NO
2 + 2 H
2O
Solutions and crystals of lead(II) nitrate are formed in the processing of lead–
bismuth
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs ...
wastes from lead refineries.
Structure
The
crystal structure
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric pattern ...
of solid lead(II) nitrate has been determined by
neutron diffraction
Neutron diffraction or elastic neutron scattering is the application of neutron scattering to the determination of the atomic and/or magnetic structure of a material. A sample to be examined is placed in a beam of thermal or cold neutrons to ob ...
.
The compound
crystallizes
Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely de ...
in the cubic system with the lead atoms in a
face-centred cubic system. Its
space group
In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it uncha ...
is Pa3
Z=4 (
Bravais lattice
In geometry and crystallography, a Bravais lattice, named after , is an infinite array of discrete points generated by a set of discrete translation operations described in three dimensional space by
: \mathbf = n_1 \mathbf_1 + n_2 \mathbf_2 + n ...
notation), with each side of the cube with length 784
picometre
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the International System of Units (SI), equal to , or one trillionth of ...
s.
The black dots represent the lead atoms, the white dots the nitrate groups 27 picometres above the plane of the lead atoms, and the blue dots the nitrate groups the same distance below this plane. In this configuration, every lead atom is
bonded to twelve oxygen atoms (
bond length: 281 pm). All N–O bond lengths are identical, at 127 picometres.
Research interest in the crystal structure of lead(II) nitrate was partly based on the possibility of free internal rotation of the nitrate groups within the crystal lattice at elevated temperatures, but this did not materialise.
Chemical properties and reactions
Lead nitrate decomposes on heating, a property that has been used in
pyrotechnics
Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition ...
.
It is soluble in water and dilute nitric acid.
Basic nitrates are formed in when alkali is added to a solution. Pb
2(OH)
2(NO
3)
2 is the predominant species formed at low pH. At higher pH Pb
6(OH)
5(NO
3) is formed.
The cation
6O(OH)6">b6O(OH)6sup>4+ is unusual in having an oxide ion inside a cluster of 3 face-sharing PbO
4 tetrahedra.
There is no evidence for the formation of the hydroxide, Pb(OH)
2, in aqueous solution below
pH 12.
Solutions of lead nitrate can be used to form co-ordination complexes. Lead(II) is a
hard acceptor; it forms stronger complexes with
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
and
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...
electron-donating ligands. For example, combining lead nitrate and
pentaethylene glycol (EO
5) in a solution of
acetonitrile
Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula and structure . This colourless liquid is the simplest organic nitrile ( hydrogen cyanide is a simpler nitrile, but the cyanide anion is not clas ...
and
methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is ...
followed by slow
evaporation
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when h ...
produced the compound
3)2(EO5)">b(NO3)2(EO5) In the crystal structure for this compound, the EO
5 chain is wrapped around the lead ion in an
equatorial plane similar to that of a
crown ether. The two bidentate nitrate
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's elect ...
s are in
trans configuration. The total
coordination number is 10, with the lead ion in a bicapped
square antiprism molecular geometry.
The complex formed by lead nitrate with a
bithiazole bidentate N-donor ligand is binuclear. The crystal structure shows that the nitrate group forms a bridge between two lead atoms.
One interesting aspect of this type of complexes is the presence of a physical gap in the
coordination sphere; i.e., the ligands are not placed symmetrically around the metal ion. This is potentially due to a lead
lone pair
In chemistry, a lone pair refers to a pair of valence electrons that are not shared with another atom in a covalent bondIUPAC '' Gold Book'' definition''lone (electron) pair''/ref> and is sometimes called an unshared pair or non-bonding pair. L ...
of electrons, also found in lead complexes with an
imidazole
Imidazole (ImH) is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non ...
ligand.
Applications
Lead nitrate has been used as a heat stabiliser in nylon and polyesters, as a coating for
photothermographic paper, and in
rodenticide
Rodenticides are chemicals made and sold for the purpose of killing rodents. While commonly referred to as "rat poison", rodenticides are also used to kill mice, squirrels, woodchucks, chipmunks, porcupines, nutria, beavers, and voles. Despi ...
s.
Heating lead nitrate is convenient means of making
nitrogen dioxide
Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the productio ...
:
2 Pb(NO_3)_2-> DeltaPbO + 4NO_2 +O_2
In the
gold cyanidation process, addition of lead(II) nitrate solution improves the
leaching process. Only limited amounts (10 to 100 milligrams lead nitrate per kilogram gold) are required.
In organic chemistry, it may be used in the preparation of
isothiocyanate
In organic chemistry, isothiocyanate is the functional group , formed by substituting the oxygen in the isocyanate group with a sulfur. Many natural isothiocyanates from plants are produced by enzymatic conversion of metabolites called glu ...
s from
dithiocarbamates.
Its use as a
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardant ...
scavenger during
SN1 substitution has been reported.
[
]
Safety
Lead(II) nitrate is toxic, and ingestion may lead to acute lead poisoning, as is applicable for all soluble lead compounds.
All
inorganic lead compounds are classified by the
International Agency for Research on Cancer
The International Agency for Research on Cancer (IARC; french: Centre International de Recherche sur le Cancer, CIRC) is an intergovernmental agency forming part of the World Health Organization of the United Nations.
Its role is to conduct and ...
(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
A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and second ...
and
lung cancer
Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, mali ...
in humans, although studies of workers exposed to lead are often complicated by concurrent exposure to
arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...
.
Lead is known to substitute for
zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
in a number of
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
s, including
δ-aminolevulinic acid dehydratase (porphobilinogen synthase) in the
haem
Heme, or haem (pronounced /Help:IPA/English, hi:m/ ), is a precursor (chemistry), precursor to hemoglobin, which is necessary to bind oxygen in the bloodstream. Heme is biosynthesized in both the bone marrow and the liver.
In biochemical terms, ...
biosynthetic pathway and
pyrimidine-5′-nucleotidase, important for the correct metabolism of
DNA and can therefore cause fetal damage.
References
External links
*
*
*
*
;Material Safety Data Sheets
MSDS for lead nitrate, PTCL, Oxford University
{{DEFAULTSORT:Lead(Ii) Nitrate
IARC Group 2A carcinogens
Lead(II) compounds
Nitrates
Oxidizing agents