Igcse Model Questions Vol1 2018 Chemistry Question 8

Practice essay / theory question 8 from the 2018 Igcse Model Questions Vol1 Chemistry examination. This question covers Solubility, Ksp, Common‑ion effect, Precipitation .

Igcse Model Questions Vol1 2018 Chemistry Essay / Theory
Topics: Solubility Ksp Common‑ion effect Precipitation
Question 8 IGCSE_MODEL_QUESTIONS_VOL1 • 2018 • CHEMISTRY • essay

A laboratory investigation studies the solubility of lead(II) iodide, PbI₂, at 25 °C. The solubility‑product constant is Ksp = 8.5 × 10⁻⁹. In a first experiment the solid is placed in pure water until equilibrium is reached. In a second experiment 0.010 mol of NaI is dissolved in 250 mL of water and excess solid PbI₂ is added, also reaching equilibrium. In a third experiment solid NaCl (0.20 mol) is added to the saturated solution from the second experiment.

Question Parts

( a )
Write the dissolution equilibrium equation for PbI₂ and express the Ksp expression in terms of ion concentrations.
( b )
Calculate the molar solubility of PbI₂ in pure water at 25 °C.
( c )
In the solution that already contains 0.010 mol of I⁻ from NaI (volume = 250 mL), determine the concentration of Pb²⁺ ions at equilibrium. Show all reasoning.

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About This Question

This is Igcse Model Questions Vol1 2018 Chemistry Question 8. It is one of the essay questions from the 2018 Igcse Model Questions Vol1 Chemistry examination.

The question covers Solubility, Ksp, Common‑ion effect, Precipitation .

View More Igcse Model Questions Vol1 2018 Chemistry Questions More Igcse Model Questions Vol1 Practice Questions Back to Questions

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