equilibrium chemistry

Question

230 mL of 0.0015 mol/L silver nitrate is added to 130 mL of 0.010 mol/L calcium acetate. Does a precipitate form? Ksp for silver acetate is 0.0020.

Answer 1

We need to calculate Q (reaction quotient) and compare that to the Ksp.

Silver nitrate = AgNO₃

Calcium acetate = Ca(C₂H₃O₂)₂

Reaction:

2AgNO₃(aq) + Ca(C₂H₃O₂)₂(aq) ==> 2AgC₂H₃O₂(s) + Ca(NO₃)₂(aq)

Tota volume = 230 ml + 130 ml = 360 ml = 0,360 L

[Ag⁺] = 0.230 L x 0.0015 mol/L = 3.45x10^-4 mol / 0.360 L = 0.000958 M

[C₂H₃O₂^-] = 0.130 L x 0.010 mol/L = 0.0013 mol / 0.360 L = 0.00361 M

Calculation of Q:

AgC₂H₃O₂(s) <==> Ag+(aq) + C₂H₃O₂^-(aq)

Q = [ Ag⁺][C₂H₃O₂^-]

Q = [0.000958][0.00361]

Q = 3.46x10^-6

Since Q is much less than Ksp, there should be no precipitate formed