Question

The student placed 10 mL of PbCl2 (saturated solution) in the test tube and added a pinch of lead acetate. When the test tube was shaken, a white precipitate of PbCl2 formed. As lead acetate is added, how is this affecting the QUANTITY of PbCl2?

Answer 1

PbCl₂(s) ⇄ Pb²⁺(aq) + 2Cl⁻(aq)

Pb(CH₃COO)₂(s) → Pb²⁺(aq) + 2CH₃COO⁻(aq)

At lead acetate disolution, concentration of lead cations will increase. According to Le Chatelie's principle equilibrium will be displaced towards formation of solid lead chloride.