Question

Copper(I) chloride has K_sp = 1.7 × 10^-7. Calculate the molar solubility of copper(I) chloride in pure water and in various aqueous solutions.

a. Calculate the molar solubility of CuCl in pure water. b. Calculate the molar solubility of CuCl in 0.0200 M HCl solution. c. Calculate the molar solubility of CuCl in 0.200 M HCl solution. d. Calculate the molar solubility of CuCl in 0.300 M CaCl₂ solution

Answer 1

a)
CuCl    ---> Cu+ + Cl-
                        s          s

Ksp = s*s
1.7*10^-7 = s^2
s=4.12*10^-4 M
Answer: 4.12*10^-4 M

b)
0.02 M HCl will give 0.02 M Cl- from begining

CuCl    ---> Cu+ + Cl-
                        s          0.02+s
Ksp = s*(0.02+s)
1.7*10^-7 = s*(0.02+s)
Since Ksp is very small, s will be very small and it can be ignored as compared to 0.02
so above expression becomes,
1.7*10^-7 = s*0.02
s=3.4*10^-9 M
Answer: 3.4*10^-9 M

c)
0.2 M HCl will give 0.2 M Cl- from begining

CuCl    ---> Cu+ + Cl-
                        s          0.2+s
Ksp = s*(0.02+s)
1.7*10^-7 = s*(0.2+s)
Since Ksp is very small, s will be very small and it can be ignored as compared to 0.2
so above expression becomes,
1.7*10^-7 = s*0.2
s=3.4*10^-8 M
Answer: 3.4*10^-8 M

d)
0.3 M CaCl2 will give 2*0.3=0.6 M Cl- from begining

CuCl    ---> Cu+ + Cl-
                        s          0.6+s
Ksp = s*(0.02+s)
1.7*10^-7 = s*(0.6+s)
Since Ksp is very small, s will be very small and it can be ignored as compared to 0.6
so above expression becomes,
1.7*10^-7 = s*0.6
s=1.02*10^-7 M
Answer: 1.02*10^-7 M