Double Displacement Chemistry Example 4

Solution

1. 1
   Reactants: $\text{Pb(NO}_3)_2$ and $\text{KI}$. In double displacement, cations swap anions.
2. 2
   Products: $\text{PbI}_2$ and $\text{KNO}_3$. Balanced: $\text{Pb(NO}_3)_2 + 2\text{KI} \rightarrow \text{PbI}_2\downarrow + 2\text{KNO}_3$.
3. 3
   The yellow precipitate is lead(II) iodide ($\text{PbI}_2$). Solubility rules: most iodides are soluble EXCEPT those of $\text{Pb}^{2+}$, $\text{Ag}^+$, and $\text{Hg}_2^{2+}$. All nitrates are soluble.