Question

Determine if AgCl precipitates out of solution when 200 mL of 1.0x10x-4 M AgNO3(aq) is mixed with 900 mL of 1.0x10-6M KCl(aq). Ksp AgCl = 1.6x10-10

Answer 1

Lets find the concentration after mixing for AgNO3

Concentration after mixing = mol of component / (total volume)

M(AgNO3) after mixing = M(AgNO3)*V(AgNO3)/(total volume)

M(AgNO3) after mixing = 1.0E-4 M*200.0 mL/(200.0+900.0)mL

M(AgNO3) after mixing = 1.818*10^-5 M

Lets find the concentration after mixing for KCl

Concentration after mixing = mol of component / (total volume)

M(KCl) after mixing = M(KCl)*V(KCl)/(total volume)

M(KCl) after mixing = 1.0E-6 M*900.0 mL/(900.0+200.0)mL

M(KCl) after mixing = 8.182*10^-7 M

So, we have now

[Ag+] = 1.818*10^-5 M

[Cl-] = 8.182*10^-7 M

At equilibrium:

AgCl <----> Ag+ + Cl-

Qsp = [Ag+][Cl-]

Qsp = (1.818*10^-5)*(8.182*10^-7)

Qsp = 1.488*10^-11

we have,

Ksp = 1.6*10^-10

Since Qsp is less than ksp, precipitate will not form

Answer: No precipitate