Exercise 8 | Solubility and Precipitation Reactions

Does Ag2SO4 (s) precipitate if we mix 100.0 mL of 0.100 M AgNO3 (aq) with 100.0 mL of 0.150 M H2SO4 (aq)?


Data: Ksp (Ag2SO4) = 1.2 x 10-5 3

Chemical reaction: Ag2SO4 (s)  2 Ag+ (aq) + SO42- (aq)


Let’s calculate Qsp:

Qsp = [Ag+]02 x [SO42-]0

[Ag+]0 = [AgNO3] x VAgNO3 / Vtot = 0.100 x 0.100 / 0.200 = 5.00 x 10-2 M

[SO42-]0 = [H2SO4] x VH2SO4 / Vtot = 0.150 x 0.100 / 0.200 = 7.50 x 10-2 M


⇒ Qsp = 1.875 x 10-4 M3

⇒ Qsp > Ksp


Ag2SO4 (s) will precipitate from the solution