Lead ions can be precipitated from aqueous solutions by the addition of aqueous iodide: Pb²⁺(aq) + 2 I^-(aq) → PbI₂(s)
Lead iodide is virtually insoluble in water so that the reaction appears to go to completion.How many milliliters of 1.500 M HI(aq) must be added to a solution containing 0.300 mol of Pb(NO₃) ₂(aq) to completely precipitate the lead?

Question

Quizplus · Accepted Answer

To completely precipitate the lead, the stoichiometry of the reaction shows that 2 moles of HI are required for every mole of Pb(NO3)2. Given 0.300 mol of Pb(NO3)2, we need 0.600 mol of HI. Using the concentration of HI (1.500 M), the volume of HI solution needed is calculated as follows: Volume = moles / concentration = 0.600 mol / 1.500 mol/L = 0.400 L, which is 400 mL.

Lead Ions Can Be Precipitated from Aqueous Solutions by the Addition