Question
Question: When equal volumes of the following solutions are mixed, precipitation of AgCl ($K_{sp}$ = 1.8×10$^{...
When equal volumes of the following solutions are mixed, precipitation of AgCl (Ksp = 1.8×10−10) will occur only with

10−4M (Ag+) and 10−4 M (Cl−)
10−5 M (Ag+) and 10−5 M (Cl−)
10−6 M (Ag+) and 10−6 M (Cl−)
10−10 M (Ag+) and 10−10 M (Cl−)
(a)
Solution
When equal volumes of two solutions are mixed, the concentration of each solute is halved. Precipitation of AgCl occurs when the ionic product (Qsp) exceeds the solubility product (Ksp). The ionic product is calculated as the product of the concentrations of Ag+ and Cl− ions after mixing. For option (a), initial concentrations are 10−4 M for both ions. After mixing equal volumes, concentrations become 0.5×10−4 M for each. The ionic product is (0.5×10−4)×(0.5×10−4)=0.25×10−8=2.5×10−9. The given Ksp is 1.8×10−10. Since 2.5×10−9>1.8×10−10, precipitation occurs in this case. For other options, the calculated ionic product is less than the Ksp, so precipitation does not occur.