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Lead(II) Nitrate

Pb(NO3)2 salt

Properties

StateSolid (white crystalline)
ColorWhite (colorless crystals)
SolubilitySoluble in water (565 g/L at 20°C)
Melting Point270°C (decomposes)
Boiling PointDecomposes before boiling

About Lead(II) Nitrate

Lead(II) nitrate is one of the rare lead salts that actually dissolves in water — 565 g/L at 20 °C — which is exactly why every Pb(II) reaction you ever ran in a teaching lab probably started from this bottle. Most lead salts are stubbornly insoluble (PbSO4, PbS, PbCO3, PbI2, PbCrO4 all live below 0.1 g/L), so when you need a pile of free Pb-2+ ions in solution, you reach for Pb(NO3)2 and let the spectator NO3- ride along. The most theatrical use is the golden rain demo: 0.1 M Pb(NO3)2 mixed with 0.1 M KI gives an immediate yellow PbI2 precipitate, but if you heat the suspension until the PbI2 redissolves and let it cool slowly in front of the class, the solution flashes with sparkling hexagonal gold-yellow platelets settling out — high-school chemistry's most reliable wow moment. The same starting reagent drives the K2CrO4 test for chromate-yellow PbCrO4 and the gravimetric determination of sulfate as PbSO4. Outside the teaching lab, Pb(NO3)2 sees use as a cyanide-leaching accelerator in some gold ores (the Habashi process), as a heat stabilizer in nylon and PVC formulations, and historically as an oxidizer in safety matches and pyrotechnic compositions. Most consumer applications have been phased out under REACH.

Where you'll encounter it

If you've ever done the golden rain demonstration in a chemistry classroom — pouring KI into Pb(NO3)2, heating until the yellow precipitate disappears, then watching glittering gold-yellow platelets crystallize out of the cooling solution — you've watched lead(II) nitrate's solubility do all the work. The reason instructors keep coming back to this one is simple: nearly every other lead salt sits at the bottom of the solubility table (PbSO4, PbS, PbCO3, PbCrO4 all below 0.1 g/L), so when you need free Pb-2+ in solution for a precipitation demo, gravimetric sulfate determination, or a chromate-yellow confirmation, Pb(NO3)2 is the only practical starting point. Modern qual-lab instructors handle the bottle in a fume hood with nitrile gloves and route every drop of waste to the hazardous-lead stream, because blood-lead action levels have dropped to 30 µg/dL.

Common Uses

  • Source of soluble Pb(II) for the golden-rain demonstration with KI
  • Reagent for confirmatory yellow PbCrO4 precipitation in qual analysis
  • Gravimetric reagent for sulfate determination as PbSO4 (alternative to BaCl2)
  • Cyanide-leaching accelerator in the Habashi process for refractory gold ores
  • Heat stabilizer in nylon and PVC polymer formulations (legacy)
  • Oxidizer in match-head and special-effect pyrotechnic compositions (largely phased out)
  • Starting material for synthesizing other lead salts (acetate, chromate, iodide)
  • Mordant in textile dyeing for certain natural fiber applications

Safety Information

Toxic and oxidizing. OSHA PEL 50 µg/m3 inorganic lead (8-hr TWA), blood-lead action level 30 µg/dL. NO3- counterion makes Pb(NO3)2 a Category 3 oxidizer (GHS03) — keep away from organics, sulfur, and finely divided metals. Full GHS profile: H272 (intensifies fire), H302 (harmful if swallowed), H332 (harmful if inhaled), H360Df (reproductive toxicity), H373 (chronic organ damage), H410 (very toxic to aquatic life). Handle in fume hood with nitrile gloves; segregate from combustibles in storage; lead waste goes to hazardous waste, never down the drain.

This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals.

Constituent Elements

Frequently Asked Questions

What is the molar mass of lead(II) nitrate?
Pb(NO3)2 is 331.21 g/mol — Pb (207.2) + 2 N (2 x 14.007 = 28.014) + 6 O (6 x 15.999 = 95.994). For a 0.100 M solution you weigh 33.12 g per liter, which is the standard concentration for the golden rain demo and for sulfate gravimetry.
What is the golden rain reaction?
Mix 0.1 M Pb(NO3)2 with 0.1 M KI: Pb(NO3)2 + 2 KI -> PbI2 + 2 KNO3. The yellow PbI2 precipitates immediately. Heat the suspension to about 80 °C and the PbI2 redissolves (its solubility climbs from 0.07 to 0.41 g/100 mL between 20 and 100 °C). Let it cool undisturbed and PbI2 crystallizes back out as flat hexagonal gold-yellow platelets that catch the light like falling gold flakes.
Why is lead(II) nitrate toxic?
Once dissolved, Pb-2+ ions bind to sulfhydryl groups on enzymes — most notably delta-aminolevulinic acid dehydratase in the heme biosynthesis pathway, which is why lead exposure causes anemia. Lead also displaces calcium in bone and accumulates with a half-life of decades. The blood-brain barrier in young children is more permeable, so chronic exposures that an adult would tolerate cause irreversible cognitive deficits in kids. The CDC reference value is now 3.5 µg/dL whole blood.