Why does water not dissolve motor oil?

검증된 단계별 안내

Understand the principle of solubility: 'Like dissolves like.' This means that polar substances dissolve in polar solvents, and nonpolar substances dissolve in nonpolar solvents.

Recognize that water is a polar molecule. Its polarity arises from the difference in electronegativity between hydrogen and oxygen atoms, creating a partial positive charge on hydrogen and a partial negative charge on oxygen.

Identify that motor oil is a nonpolar substance. Motor oil consists of long hydrocarbon chains, which lack significant electronegativity differences and do not form dipoles.

Explain that polar molecules like water cannot effectively interact with nonpolar molecules like motor oil. Water molecules are strongly attracted to each other through hydrogen bonding, and they do not form similar interactions with nonpolar molecules.

Conclude that because water and motor oil have different polarities, they are immiscible, meaning they do not mix or dissolve in each other.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Polarity

Polarity refers to the distribution of electrical charge over the atoms in a molecule. Water is a polar molecule, meaning it has a partial positive charge on one side and a partial negative charge on the other. This polarity allows water to form hydrogen bonds and interact effectively with other polar substances, but it does not interact well with non-polar substances like motor oil.

Hydrophobic and Hydrophilic Interactions

Hydrophobic interactions occur between non-polar substances that repel water, while hydrophilic interactions occur between polar substances that attract water. Motor oil is hydrophobic, meaning it does not mix with water. This is because the non-polar molecules in motor oil do not form favorable interactions with the polar water molecules, leading to separation rather than dissolution.

Solubility Principles

Solubility is the ability of a substance to dissolve in a solvent, which is influenced by the nature of both the solute and the solvent. The principle 'like dissolves like' suggests that polar solvents dissolve polar solutes, and non-polar solvents dissolve non-polar solutes. Since water is polar and motor oil is non-polar, they do not dissolve in each other, illustrating this principle.