is Q greater, equal, or less than Ksp

Question

The K_sp of AgCl at 25 ^oC is 1.6 x 10^-10. Consider a solution that is 1.0 x 10^-2 M in CaCl₂ and 1.0 x 10^-8 M in AgNO₃.

Answer 1

Answer 2

CaCl₂(aq) + 2AgNO₃(aq) ==> AgCl(s) + Ca(NO₃)₂(aq)

AgCl(s) ==> Ag⁺(aq) + Cl^-(aq)

Q = [Ag⁺][Cl^-]

[Ag⁺] = 1.0x10^-8 M

[Cl^-] = 1.0x10^-2 x 2 = 2.0x10^-2 because CaCl₂ => 2Cl^-

Q = (1.0x10^-8)(2.0x10^-2)

Q = 2x10^-10

Q > Ksp (Q is greater than Ksp)