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.How many milliliters of 3.550 M HI(aq) must be added to a solution containing 0.700 mol of Pb(NO₃) ₂(aq) to completely precipitate the lead?

Question

Quizplus · Accepted Answer

To completely precipitate the lead, 1.40 mol of HI is required. The volume of 3.550 M HI required is:$$1.40	ext{ mol HI}	imes\frac{1	ext{ L HI}}{3.550	ext{ mol HI}}=0.394	ext{ L}=394	ext{ mL}$$

Lead Ions Can Be Precipitated from Aqueous Solutions by the Addition