======Lead Iodide Precipitation======


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**Alternative titles:** [[golden_rain|Golden Rain]]
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====Summary====                   
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====Procedure====  
  - Dissolve lead(II) nitrate in water to form a clear solution.  
  - Dissolve potassium iodide in a separate container of water.  
  - Mix the two solutions together.  
  - Observe the immediate formation of a bright yellow precipitate of lead(II) iodide.


====Links==== 
Lead Nitrate and Potassium Iodide - Chemistry and Biochemistry Demo lab at OSU: 
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📄 What happens when lead nitrate reacts with potassium iodide - Unacademy: [[https://unacademy.com/content/question-answer/chemistry/what-happens-when-lead-nitrate-reacts-with-potassium-iodide/]]\\


====Variations====
  * Compare the reaction at room temperature with the heated and cooled version ([[golden_rain|Golden Rain]]).  
  * Vary concentrations to see how the intensity of the precipitate changes.  
  * Demonstrate other double displacement reactions (e.g., silver nitrate with sodium chloride) for comparison.



====Safety Precautions====
  * Lead salts are highly toxic — avoid ingestion, inhalation, or skin contact.  
  * Always wear safety glasses, gloves, and a lab coat. 
  * Do not dispose of lead-containing waste down the drain; collect and store as hazardous waste.




====Questions to Consider====
  * What type of reaction occurs between lead nitrate and potassium iodide? (Double displacement, also called metathesis.)  
  * Why does a precipitate form immediately? (PbI₂ is insoluble in cold water, unlike KNO₃ which remains dissolved.)  
  * What color is the precipitate and why? (Yellow, due to the properties of lead(II) iodide crystals.)  
  * How does heating the solution change the result? (PbI₂ dissolves in hot water and recrystallizes as golden flakes upon cooling.)  
  * What real-world hazards are associated with lead compounds? (They are toxic and environmentally harmful.)