The correct option is A 10−4M Ag+ and 10−4M Cl−
Given, AgCl (Ksp=1.8×10−10)
For precipitation the ionic product should exceed solubility product (Ksp).
(a) 10−4M Ag+ and 10−4M Cl−
[Ag+][Cl−]=(10−4×10−4)=10−8M2
[Ag+][Cl−]=10−8>K0sp=1.8×10−10)
Hence, precipitation will take place.
b) 10−5M Ag+ and 10−5M Cl−
[Ag+][Cl−]=(10−5×10−5)=10−8M2
[Ag+][Cl−]=10−10<K0sp=1.8×10−10)
Hence, no precipitation will take place.
c) 10−6M Ag+ and 10−6M Cl−
[Ag+][Cl−]=(10−6×10−6)=10−12M2
[Ag+][Cl−]=10−12<K0sp=1.8×10−10)
Hence, no precipitation will take place.
d) 10−10M Ag+ and 10−10M Cl−
[Ag+][Cl−]=(10−10×10−10)=10−20M2
[Ag+][Cl−]=10−20<K0sp=1.8×10−10)
Hence, no precipitation will take place.