Final answer:
Adding sodium sulfate solution to copper(II) chloride solution does not result in a precipitate, and the light blue color of the solution is maintained. The color change in the equilibrium state is influenced by the electronic interaction of ions, in the absence of precipitate formation, indicating a stable equilibrium without significant change.
Step-by-step explanation:
When sodium sulfate solution is added to a mixture in equilibrium, such as a copper(II) chloride solution, there can be observable changes in the color of the mixture. This phenomenon can be better understood by looking at the interaction of dissolved ions within the solution and their effect on the equilibrium state. In the scenario where no precipitate forms, only the intrinsic properties of the solutions and their interactions can cause a color change. As reported, the addition of sodium sulfate to copper(II) chloride solution does not result in a precipitate and the solution remains a light blue color. This indicates that the ions present do not undergo a significant reaction that changes the color of the solution.
The colors seen in such equilibrium reactions are often due to the complex ions formed in the solutions and their electronic structures, as with the copper sulfate example, where water molecules coordinate with the copper ions, affecting the d electron configurations and resulting in a characteristic color. When sodium sulfate is added to a saturated solution of another salt, the addition of ions could potentially shift the equilibrium and trigger the precipitation of some ions, which could alter the color.
In the case of the reaction, Na₂SO₄(aq) + CuCl₂(aq) → NaCl(aq) + CuSO₄(aq), there is no formation of a precipitate, and the light blue color is due to the stable copper sulfate complex in the solution. Thus, the equilibrium is maintained without a significant color change in the presence of sodium sulfate.