Great question! The key idea here is “like dissolves like”:

• Polar solutes dissolve best in polar solvents (like water).

• Nonpolar solutes dissolve best in nonpolar solvents (like carbon tetrachloride, CCl₄).

Solutes:

1. C₆H₆ (benzene) – nonpolar → dissolves better in CCl₄.

2. I₂ (iodine) – nonpolar → dissolves better in CCl₄.

3. Na₂S (sodium sulfide) – ionic and very polar → dissolves better in water.

4. CH₃OH (methanol) – polar, forms hydrogen bonds → dissolves better in water.

Final Answer:

• C₆H₆ → carbon tetrachloride

• I₂ → carbon tetrachloride

• Na₂S → water

• CH₃OH → water