Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: a. too much solid has dissolved. / b. additional precipitate is forming. / c. the solution is unsaturated. / d. the ions are now combining to reduce their concentrations.

The correct answer is option D, that is, the ions are now combining to reduce their concentrations.

Explanation:

On the basis of the chemical equation:  

PbCl₂ (s) ⇒ Pb²⁺ (aq) + 2Cl⁻ (aq)

It is mentioned that the value of Ksp is 1.8 × 10⁻²

As the solubility product is very less or negligible for this reaction that signifies that the ions produced are getting combined, resulting in the reduction of the concentration of the ions and enhancing the formation of the solid lead chloride. Therefore, they associate together to produce solid lead chloride.