Question

A chemist requires a solution of 2.00 M Fe2+ for an experiment. (The Ksp of Fe(OH)2 is 4.9x10-17) a) Will the precipitation of Fe(OH)2 (s) be an issue if the solution is prepared with pure water at 25°C? b) [1 pt] What might the chemist do to prepare this Fe2+ solution to the desired concentration?

Answer 1

The pH of water at 25C is 7 i.e. the conc of hydroxide would be  $10^{^{-7}}$M.

Qsp is the ionic product. Ksp is the solubility product. When Qsp is greater than Ksp, it results in the formation of precipitate.

To make the solution of desired concentration, one should decrease the Qsp value. This can be done by increasing the pH. i.e by making the solution more alkaline.