Final answer:
When copper (II) sulfate is mixed with sodium sulfide, a double displacement reaction occurs, and copper (II) sulfide is formed as a precipitate. The solution may appear cloudy or milky due to the solid particles of copper (II) sulfide. The presence of copper (II) ions gives the solution a light blue color.
Step-by-step explanation:
When you mix 1 ml of 0.1 M copper (II) sulfate with 5 ml of 0.1 M sodium sulfide, a chemical reaction called a double displacement reaction occurs. In this reaction, the copper (II) ions (Cu²⁺) from the copper (II) sulfate react with the sulfide ions (S²⁻) from the sodium sulfide to form a new compound called copper (II) sulfide (CuS).
This compound appears as a precipitate, which means it is insoluble and forms solid particles in the solution.
The chemical equation for this reaction is:
CuSO₄ + Na₂S → CuS + Na₂SO₄
The precipitate will appear as a solid in the solution, giving it a cloudy or milky appearance. In this case, since copper (II) sulfate is a blue compound, the resulting solution may have a light blue color due to the presence of copper (II) ions.