Answer to Question #187014 in General Chemistry for Inbo Shim

Question

1. The Ksp values for Fe(OH)3 and Al(OH)3 are given in the lower table above. A 1.0 g sample of powdered Fe2O3(s) and a 1.0 g sample of powdered Al2O3(s) are mixed together and placed in 1.0 L of distilled water.

Which ion, Fe3+(aq) or Al3+(aq), will be present in the higher concentration? Justify your answer with respect to the Ksp values provided.

Write a balanced chemical equation for the dissolution reaction that results in the production of the ion that you identified in part (i).

Answer 1

The dissociation constant for trivalent Fe compounds is lower than for Al compounds. Consequently, Al compounds are more soluble in water. Their concentration is higher even with equal amounts of the substance.