Multiple Choice
Lead ions can be precipitated from aqueous solutions by the addition of aqueous iodide: Pb2+(aq) + 2I-(aq) → PbI2(s). Lead iodide is virtually insoluble in water so that the reaction appears to go to completion. If you have 50.0 mL of a 0.100 M Pb(NO3)2 solution, how many milliliters of 3.550 M HI(aq) are needed to completely precipitate the lead ions as PbI2?