NEET2011ChemistryIonic EquilibriumActual
In qualitative analysis, the metals of group I can be separated from other ions by precipitating them as chloride salts. A solution initially contains Ag ⁺ and Pb ²⁺ at a concentration of 0.10 M . Aqueous HCl is added to this solution until the Cl ⁻ concentration is 0.10 M . What will be the concentration of Ag ⁺ and Pb ²⁺ be at equilibrium? ( K_ sp for AgCl =1.8 10⁻¹⁰, K_ sp for PbCl ₂=1.7 10⁻⁵ )
Options
- A[ Ag ⁺ ]=1.8 10⁻⁷ M ; [ Pb ²⁺ ]=1.7 10⁻⁶ M
- B[ Ag ⁺ ]=1.8 10⁻¹¹ M ; [ Pb ²⁺ ]=8.5 10⁻⁵ M
- C[ Ag ⁺ ]=1.8 10⁻⁹ M ; [ Pb ²⁺ ]=1.7 10⁻³ M
- D[ Ag ⁺ ]=1.8 10⁻¹¹ M ; [ Pb ²⁺ ]=8.5 10⁻⁴ M
Correct answer
C. [ Ag ⁺ ]=1.8 10⁻⁹ M ; [ Pb ²⁺ ]=1.7 10⁻³ M
Step-by-step solution
K_ sp for AgCl = [ Ag ⁺ ] [ Cl ⁻ ] aligned [ Ag ⁺ ] & = 1.8 10⁻¹⁰ 10⁻¹ & =1.8 10⁻⁹ M . K_ sp for PbCl ₂ & = [ Pb ²⁺ ] [ Cl ⁻ ]^2 [ Pb ²⁺ ] & = 1.7 10⁻⁵ 10⁻¹ 10⁻¹ & =1.7 10⁻³ M aligned