Question

which statement best explains why oil and water do not mix? water molecules are carbon - based and oil molecules are not. water molecules are polar and oil molecules are nonpolar. oil molecules are polar and water molecules are nonpolar. oil and water both have covalent bonds and repel one another.

Explanation:

• Water molecules are polar (due to the difference in electronegativity between oxygen and hydrogen, creating a dipole moment).
• Oil molecules are non - polar (composed mainly of hydrocarbon chains with relatively even distribution of electron density).
• "Like dissolves like" principle: polar substances tend to dissolve in polar solvents, and non - polar substances in non - polar solvents. Since water is polar and oil is non - polar, they do not mix.

Answer:

Water molecules are polar and oil molecules are nonpolar.