Lead Iodide formula also referred to as Lead (II) Iodide formula or Plumbous Iodide formula is mentioned in this article. It is an extremely toxic salt and has terrible stability. The molecular formula of Lead Iodide is PbI2. Plumbous Iodide is a crystalline solid bright which is yellow in color at room temperature. The color changes to orange and further to red when it heats. It is having no smell and is denser than water. It doesn't dissolve in water. It is used in photography, printing, manufacturing solar cells, etc. It can be synthesized by a reaction known as a double displacement reaction. In this reaction potassium iodide and lead (II) nitrate are made to react in a water solution.