Use the result of the Integrative Example to determine whether a solution can be prepared with [Cu⁺] equal to 

(a) 0.20 M; 

(b) 1.0 x 10^–10 M.

Integrative Example

Although a number of slightly soluble copper(I) compounds (such as CuCN) can exist in contact with water, it is not possible to prepare a solution with a high concentration of Cu⁺ ion. Show that Cu⁺(aq) disproportionates to Cu²⁺(aq) and Cu(s), and explain why a high [Cu⁺] cannot be maintained in aqueous solution.