To determine which of the given substances is most likely to dissolve in water, we need to consider their molecular properties.
1. **Oil:** Oil is nonpolar and does not mix with water because water is a polar solvent. Therefore, oil does not dissolve in water.
2. **Hexane (C6H14):** Hexane is a nonpolar molecule, similar to oil, and would not dissolve well in water due to the mismatch in polarity between hexane and water.
3. **Vinegar (CH3COOH):** Vinegar, which contains acetic acid (CH3COOH), is a polar molecule. The presence of the -COOH group makes it capable of forming hydrogen bonds with water molecules, enabling it to dissolve in water.
4. **Carbon tetrachloride (CCl4):** Carbon tetrachloride is a nonpolar molecule, like oil and hexane, and does not dissolve in water for the same reasons as the other nonpolar substances.
Therefore, the substance most likely to dissolve in water from the given options is **III. Vinegar (CH3COOH)** due to its polar nature and ability to form hydrogen bonds with water molecules. Oil, hexane, and carbon tetrachloride are nonpolar substances that do not readily dissolve in water.
