We are asked to identify which ions remain after PbI₂ precipitates in the given reaction:

2 KI(aq) + Pb(NO₃)(aq) → 2 KNO₃(aq) + PbI₂(s)

We will refer to the solubility rules shown below:

Solubility Rules:

•Soluble Ionic Compounds:

▪ Group 1A ions (Li⁺, Na⁺, K⁺, etc.) and Ammonium ion (NH₄⁺) are soluble
▪ Nitrates (NO₃^-), Acetates (CH₃COO^- or C₂H₃O₂^-), and most Perchlorates (ClO₄^-) are soluble
▪ Cl^-, Br^-, and I^- are soluble except when paired with Ag⁺, Pb²⁺, Cu⁺, Hg₂²⁺
▪ Sulfates (SO₄^2-) are soluble except those of Ca²⁺, Sr²⁺, Ba²⁺, Ag⁺, and Pb²⁺

•Insoluble Ionic Compounds: