✔ 最佳答案
Assume that there is no change in volume when KCl is added.
PbCl₂(s) ⇌ Pb²⁺(aq) + 2Cl⁻(aq)
When maximum mass of KCl is added :
[Pb²⁺] [Cl⁻]² = Ksp
(0.010) × [Cl⁻]² = 1.6 × 10⁻⁵
[Cl⁻]² = 1.6 × 10⁻³
[Cl⁻] = 0.040 mol/L
Maximum number of moles of KCl
= Maximum number of moles of Cl⁻
= [Cl⁻] × (Volume of the solution)
= (0.040 mol/L) × (1.0 L)
= 0.040 mol
Maximum mass of KCl
= (Maximum number of moles of KCl) × (Molar mass of KCl)
= (0.040 mol) × [(39.01 + 35.45) g/mol]
= 2.98 g