Lead Iodide Precipitation (Golden Rain)

Pb(NO₃)₂ + 2KI → PbI₂↓ + 2KNO₃

Visão geral

Lead nitrate and potassium iodide form a bright yellow precipitate of lead iodide. When the hot mixture is cooled slowly, lead iodide crystallizes as golden shimmering plates, creating the spectacular golden rain demonstration. PbI₂ has a Ksp of 9.8 × 10⁻⁹ and is more soluble in hot water.

Participantes

Papel	Substância	Coeficiente	Estado
Produto	Potassium Nitrate KNO₃	2	(aq)

Exemplo do cotidiano

The golden rain experiment produces one of chemistry's most visually stunning displays as golden PbI₂ crystals settle like glittering snow.

Importância industrial

O iodeto de chumbo é precursor do iodeto de metilamónio e chumbo (perovsite), utilizado em células solares de nova geração com eficiências superiores a 25%.

Propriedades

Tipo: Precipitation
Reversível: Não
Energia: Exotérmico
ΔH: -32,0 kJ/mol

Reações relacionadas

Aluminum Hydroxide Precipitation Barium Carbonate Precipitation Barium Sulfate Precipitation Cadmium Sulfide Precipitation (Yellow) Calcium Fluoride Precipitation (Fluorite) Calcium Phosphate Precipitation (Bone Mineral) Chromium(III) Hydroxide Precipitation Lead Carbonate Precipitation Lead Chloride Precipitation Iron(III) Hydroxide Precipitation

Frequently Asked Questions

What is the equation for Lead Iodide Precipitation (Golden Rain)?

The balanced equation is: Pb(NO₃)₂ + 2KI → PbI₂↓ + 2KNO₃.

What type of reaction is Lead Iodide Precipitation (Golden Rain)?

Lead Iodide Precipitation (Golden Rain) is a precipitation reaction.

Is Lead Iodide Precipitation (Golden Rain) exothermic or endothermic?

Lead Iodide Precipitation (Golden Rain) is exothermic (releases energy). The enthalpy change (ΔH) is -32.0 kJ/mol.