When an aqueous solution of lead(ii) nitrate (Pb(NO₃)₂) is mixed with an aqueous solution of sodium iodide (NaI), an aqueous solution of sodium nitrate (NaNO₃) and a yellow solid, lead iodide (PbI₂), are formed.
The balanced equation for the reaction is:
Pb(NO₃)₂(aq)+2NaI(aq)→2NaNO₃(aq)+PbI₂(s)