Question

The common ion effect can be most effectively used to _________ precipitation of a _________ ionic solid.

Select the correct answer below:

encourage, soluble

discourage, soluble

encourage, slightly soluble

discourage, slightly soluble

Answer 1

The common ion effect is used to discourage the precipitation of a slightly soluble ionic solid by shifting the equilibrium to favour the formation of less dissolved ions.

Step-by-step explanation:

The common ion effect can be most effectively used to discourage precipitation of a slightly soluble ionic solid. Adding a common ion to a solution where a slightly soluble salt is at equilibrium will cause the solution to become supersaturated concerning that salt. According to Le Chatelier's principle, this addition will shift the equilibrium to the left, reducing the solubility of the salt and encouraging the formation of a solid precipitate from the dissolved ions.

Answer 2

The common ion effect can be used to discourage the precipitation of a slightly soluble ionic solid.

Step-by-step explanation:

The correct answer is discourage, slightly soluble. The common ion effect is a phenomenon in which the presence of a common ion in a solution reduces the solubility of an ionic compound. By adding a soluble salt that contains a common ion, the solubility of a slightly soluble ionic solid can be decreased, leading to its precipitation. This is because the common ion shifts the solubility equilibrium towards the left, causing the excess product to form a precipitate.