Final answer:
To calculate the Ksp for Pb(IO₃)₂, the solubility of 1.1×10⁻⁷ M provided is used for the concentration of Pb²+ ions, and the initial concentration of IO₃⁻ ions from KIO₃ remains unchanged. Multiply the concentration of Pb²+ by the square of the concentration of IO₃⁻ ions to find the Ksp value, which is 3.19×10⁻.
Step-by-step explanation:
The solubility of Pb(IO₃)₂ in a 1.70×10⁻² M KIO₃ solution is 1.1×10⁻⁷ mol/L. The dissolution of Pb(IO₃)₂ can be expressed as:
Pb(IO₃)₂(s) ⇌ Pb²+(aq) + 2IO₃⁻(aq)
Since the solubility of Pb(IO₃)₂ is 1.1×10⁻⁷ M, this will also be the concentration of Pb²+ ions in solution because the ratio of Pb²+ to Pb(IO₃)₂ is 1:1. The concentration of IO₃⁻ ions provided from KIO₃ does not change significantly due to the small solubility of Pb(IO₃)₂ so we can approximate the concentration of IO₃⁻ as 1.70×10⁻² M. Therefore, the Ksp can be calculated:
Ksp = [Pb²+][IO₃⁻]² = (1.1×10⁻⁷)(1.70×10⁻²)² = 3.19×10⁻