Lead(II) nitrate

Chemical properties

The lead nitrate appears as a white cubic crystal or monoclinic crystalline powder. It is soluble in water and liquid ammonia, being slightly soluble in the ethanol, being insoluble in concentrated nitric acid (produce protective film); it can react with concentrated hydrochloric acid or concentrated alkali chloride solution to form complex chlorinated lead acid or chlorinated lead acid salt; it has strong oxidizing property and may cause the risk of inducing combustion and explosion if mixed with organic matter, reducing agent and combustible substance such as sulfur and phosphorus or even subject to slightly friction. The dry lead nitrate can be subject to decomposition at around 205 ~223 while a temperature of 100 is enough to trigger the decomposition of wet lead nitrate. Its decomposition can emit toxic nitric oxide gas.

Chemical properties

Lead nitrate, Pb(NO3)2, sp gr 4.53, forms cubic or monoclinic colorless crystals. Above 205 °C, oxygen and nitrogen dioxide are driven off, and basic lead nitrates are formed. Above 470 °C, lead nitrate is decomposed to lead monoxide and Pb3O4. Lead nitrate is highly soluble in water (56.5 g/100 mL at 20 °C; 127 g/100 mL at 100 °C), soluble in alkalies and ammonia, and fairly soluble in alcohol (8.77 g/ 100 mL of 43% aqueous ethanol at 22 °C). Lead nitrate is readily obtained by dissolving metallic lead, lead monoxide, or lead carbonate in dilute nitric acid. Excess acid prevents the formation of basic nitrates, and the desired lead nitrate can be crystallized by evaporation.

Physical properties

Colorless cubic or monoclinic crystals; refractive index 1.782; density 4.53 g/cm³ at 20°C; decomposes at 470°C; soluble in cold water; very soluble in boiling water 127 g/100 mL at 100°C; also soluble in caustic soda, caustic potash and ammonia solution, and moderately soluble in alcohol.

The Uses of Lead(II) nitrate

Lead(II) nitrate is employed in industrial applications such as heat stabilization in nylon and polyesters and coatings of photothermographic paper. It is utilized to improve the leaching process in the gold cyanidation. It finds applications as a lead paint as well as a source of dinitrogen tetroxide. As an oxidant, it is used in the oxidation of benzylic halides to aldehydes in organic synthesis. It is also used in the preparation of dithiocarbamates from isothiocyanates. It acts as a scavenger of bromide in nucleophilic substitution reactions.

The Uses of Lead(II) nitrate

manufacture of matches and special explosives; as mordant in dyeing and printing on textiles; mordant for staining horn, mother-of-pearl; oxidizer in dye industry; sensitizer in photography; process engraving.

The Uses of Lead(II) nitrate

Lead nitrate is used in many industrial processes, ranging from ore processing to pyrotechnics to photothermography. Thus lead nitrate is used as a flotation agent in titanium removal from clays; in electrolytic refining of lead; in rayon delustering; in red lead manufacture; in matches, pyrotechnics, and explosives; as a heat stabilizer in nylon; as a coating on paper for photothermography; as an esterification catalyst for polyesters; as a rodenticide; as an electroluminescent mixture with zinc sulfide; as a means of electrodepositing lead dioxide coatings on nickel anodes; and as a means of recovering precious metals from cyanide solutions.

What are the applications of Application

Lead (II) nitrate is Titrant for complexometric titration

Preparation

Lead nitrate is prepared by dissolving lead metal, lead monoxide or lead carbonate in excess dilute nitric acid followed by evaporation of and/or cooling the solution for crystallization.

General Description

Lead dinitrate is a white crystalline solid. The material is soluble in water. Lead dinitrate is noncombustible but Lead dinitrate will accelerate the burning of combustible materials. If large quantities of the material are involved in the fire an explosion may result. Prolonged exposure of the material to fire or heat may result in an explosion. Toxic oxides of nitrogen are produced in fires involving Lead dinitrate.

Air & Water Reactions

Water soluble.

Reactivity Profile

Mixtures of metal/nonmetal nitrates with alkyl esters may explode because of the formation of alkyl nitrates; mixtures of nitrate with phosphorus, tin (II) chloride or other reducing agents may react explosively [Bretherick 1979. p. 108-109]. An explosion of guanidine nitrate demolished an autoclave built to withstand 50 atmospheres, in which Lead dinitrate was being made from ammonium thiocyanate and Lead dinitrate [C. Angew. Chem. 49:23. 1936].

Hazard

The toxic effects are greater than other lead salts because lead nitrate is more soluble. Moderately toxic by ingestion and other routes of exposure. The compound also is an irritant to eye, skin, and mucous membranes.

Health Hazard

Early symptoms of lead intoxicatin via inhalation or ingestion are most commonly gastrointestinal disorders, colic, constipation, etc.; weakness, which may go on to paralysis, chiefly of the extensor muscles of the wrists and less often the ankles, is noticeable in the most serious cases. Ingestion of a large amount causes local irritation of the alimentary tract; pain, leg cramps, muscle weakness, paresthesias, depression, coma, and death may follow in 1 or 2 days. Contact with eyes causes irritation.

Flammability and Explosibility

Non flammable

Industrial uses

This is a white to colorless fine crystalline compound, extremely soluble in water (34% at 20 °C). Commercial production is based on dissolution of lead metal or lead compounds in nitric acid (36–40% solution). Lead nitrate is considered to be an activator in mineral processing. Although lead may activate sphalerite, similar to CuSO₄, the use of Pb(NO₃)₂ is limited to the activation of stibnite during beneficiation of antimony ores. Lead nitrate is the most widely used chemical in cyanidation of precious metals as an accelerator.

Purification Methods

Precipitate it twice from a hot (60o) concentrated aqueous solution by adding HNO3. The precipitate is sucked dry on a sintered-glass funnel, then transferred to a crystallising dish which is covered by a clock glass and left in an electric oven at 110o for several hours [Beck et al. Trans Faraday Soc 55 331 1959]. After two recrystallisations of ACS grade, no metals above 0.001ppm were detected.