In: Chemistry
A solution contains 0.018 mol each of I– , Br– , and Cl– . Use the Ksp values given below to determine how much AgCl(s) precipitates out when this solution is mixed with 200 mL of 0.24 M AgNO3.
AgI , Ksp = 8.52×10–17
AgBr , Ksp = 5.35×10–13
AgI , Ksp = 1.77×10–10
AgNO3 (aq) + Cl- (aq) ---------------------> AgCl (s) + NO3- (aq)
Ksp of AgI and AgBr are lesser than AgCl so they could form precipitate first
actual moles of AgNO3 are present = 200 x 0.24 / 1000 = 0.048
moles of each ion present 0.018
AgNO3 moles needed for I- = 0.018
AgNO3 moles needed for Br- = 0.018
remaining AgNO3 moles = 0.048 -(0.018 +0.018)
= 0.012
now AgCl precipitation.
AgNO3 (aq) + Cl- (aq) ---------------------> AgCl (s) + NO3- (aq)
0.012 0.018 0.012
moles of AgCl formed = 0.012
mass of AgCl formed = moles x molar mass
= 0.012 x 143.32
= 1.72 g
AgCl(s) precipitates = 1.72 g