Gradual addition of potassium iodide solution to Bi(NO₃)₃ solution initially produces a dark brown precipitate which dissolves in excess of KI to give a clear yellow solution. Identify the yellow precipitate.

 Bi(NO₃)₃ undergoes hydrolysis. Nitric acid is formed which oxidizes KI to iodine. The liberated iodine dissolves in KI to form yellow solution of KI₃.

$\begin{array}{l}\mathrm{Bi}{\left({\mathrm{NO}}_3\right)}_3+{\mathrm{H}}_2\mathrm{O}⟶\left[\mathrm{Bi}\left(\mathrm{OH}\right){\left({\mathrm{NO}}_3\right)}_2\right]+{\mathrm{HNO}}_3;\\ 2{\mathrm{HNO}}_3⟶{\mathrm{H}}_2\mathrm{O}+2{\mathrm{NO}}_2+\mathrm{O}\\ 2\mathrm{KI}+{\mathrm{H}}_2\mathrm{O}+\mathrm{O}⟶2\mathrm{KOH} +\underset{\text{ Dark brown }}{{\mathrm{I}}_2};\\ {\mathrm{I}}_2+\mathrm{KI}⟶\underset{\text{ Yellow solution }}{{\mathrm{KI}}_3}\end{array}$