Question

Determine whether a precipitate will form when 200 mL of 1.5 x 10^-3 M KCl is mixed with 300 mL of 2.0 x 10-7 M Pb(NO3)2 ? Ksp PbCl2 = 1.7 x 10-

Answer 1

I.P << Ksp ⇒ precipitate will form when mixing these two substances in those quantities and concentrations

Step-by-step explanation:

• HCl → H+ + Cl-
• Pb(NO3)2 → Pb2+ + 2NO3-
• PbCl2 ↔ Pb2+ + 2Cl-

∴ Ksp PbCl2 = 1.7 E-5 = [ Cl- ]² * [ Pb2+ ]

⇒ I.P = [ Pb2+ ] * 2[ Cl- ]

∴ [ Pb2+ ] = ((2.0 E-7)*(0.300) / 0.5) = 1.2 E-7 M

∴ [ Cl- ] =((1.5 E-3)*(0.200) / 0.5) = 6 E-4 M

⇒ I.P = ( 1.2 E-7 ) * (6 E-4 ) = 7.2 E-11

∴ I.P << Ksp ⇒ precipitate formation