Final answer:
Oil is nonpolar and will dissolve in hexane, a nonpolar solvent. The other substances listed are polar or ionic and not likely to dissolve in hexane.
Step-by-step explanation:
Hexane, a nonpolar solvent, will dissolve substances that are also nonpolar due to similarity in intermolecular forces. The substances given are oil, sodium chloride, ammonium acetate, and vinegar (acetic acid).
Between these, oil is nonpolar and is expected to be soluble in hexane. Sodium chloride and ammonium acetate are ionic compounds, and vinegar is a weak acid; all three are polar or capable of forming hydrogen bonds and are not likely to dissolve well in a nonpolar solvent like hexane. Therefore, oil is the substance among the options that will dissolve in hexane.
To put it simply, the general rule of thumb for solubility is 'like dissolves like,' meaning polar solvents dissolve polar compounds and nonpolar solvents dissolve nonpolar compounds. Oil is the nonpolar substance that would dissolve in hexane, making other polar or ionic options incompatible with hexane.