Passage
Although acetylsalicylic acid (aspirin) is a well-known and widely used analgesic and anti-inflammatory agent, copper(II) acetylsalicylate, a copper complex formed from aspirin and copper, has also been found to exhibit some distinctive and potentially beneficial pharmacological properties. Formation of copper(II) acetylsalicylate is achieved when the conjugate base of aspirin, acetylsalicylate (C₉H₇O₄⁻) , binds to Cu²⁺ ions in solution, as outlined in Reaction 1.4 NaC₉H₇O₄(aq) + 2 CuSO₄(aq) → Cu₂(C₉H₇O₄) ₄(s) + 2 Na₂SO₄(aq) Reaction 1Using Reaction 1, a researcher synthesized a sample of copper(II) acetylsalicylate for analysis. A small volume of 0.50 M aqueous copper(II) sulfate (molar mass = 159.6) was mixed into 100 mL of filtered, saturated aqueous sodium acetylsalicylate (molar mass = 202.2) at room temperature and slowly stirred. Formation of copper(II) acetylsalicylate (molar mass = 843.7) was immediately observed as a bright blue precipitate. The precipitate was then isolated by filtration and dried, affording the product complex in high yield.
Adapted from: Seguel GV, Rivas BL, Contreras JG. Synthesis and characterization of copper complexes: interaction of metalliccarboxylates with 1,3-thiazole ligand. Journal of the Chilean Chemical Society. 1970; 58(4) :1967.
-The copper(II) acetylsalicylate product immediately precipitates from the reaction solution because:

Question

Quizplus · Accepted Answer

11ecba2d_11ce_4cf2_a3bf_4d440b782025_MD0008_00 The dissolution of compound Z into ions X and Y can be written as: 11ecba2d_11ce_4cf3_a3bf_4fc3325d026a_MD0008_00 The solubility product constant K_sp for the general dissolution reaction above is given by 11ecba2d_11ce_4cf4_a3bf_f74a69939c9c_MD0008_00 where [X] and [Y] are the molar concentrations of the X and Y ions, and c and d are the respective coefficients of the balanced dissolution reaction. The K_sp is the product of the maximum concentrations of each ion possible in the solution under the given conditions. As a result, the K_sp represents the limit of solubility for the compound (saturated solution). If the concentrations of [X] and [Y] are such that [X]^c[Y]^d < K_sp, the solution has not reached the solubility limit and will permit more ions into solution (dissolve more of Z). Conversely, if the concentrations of [X] and [Y] are such that [X]^c[Y]^d > K_sp, the solubility limit of the solution has been exceeded and the solution will not accept any more ions (no more Z will dissolve). This will cause any ions in excess of the K_sp to come out of solution as a precipitate. For the dissolution of Cu₂(C₉H₇O₄)₄, the maximum solubility of Cu₂(C₉H₇O₄)₄ (the K_sp) is equal to [Cu²⁺]²[C₉H₇O₄⁻]⁴. Although the numerical value of K_sp is not given, the fact that the product immediately precipitates from solution indicates that the concentrations of [Cu²⁺] and [C₉H₇O₄⁻] result in a value of [Cu²⁺]²[C₉H₇O₄⁻]⁴ that exceeds the K_sp of Cu₂(C₉H₇O₄)₄. Therefore, [Cu²⁺]²[C₉H₇O₄⁻]⁴ > K_sp. (Choice A) [Cu²⁺]²[C₉H₇O₄⁻]⁴ < K_sp indicates that the solubility limit of the product has not been exceeded and the product would not precipitate from the solution. (Choice B and D) Because K_sp = [Cu²⁺]²[C₉H₇O₄⁻]⁴ at saturation, comparisons of K_sp with the expression [Cu²⁺]² + [C₉H₇O₄⁻]⁴ are not meaningful with respect to solubility. Educational objective: In a solution formed from the dissolution of a compound into ions, the compound will dissolve until the solution reaches the value of the solubility product constant K_sp for the compound. Ion concentrations that exceed the K_sp result in precipitation of the excess.

Passage Although Acetylsalicylic Acid (Aspirin) Is a Well-Known and Widely Used