dipole moment

简明释义

偶极矩

英英释义

例句

1.Molecules with a zero dipole moment are generally nonpolar and do not interact strongly with polar solvents.

具有零偶极矩的分子通常是非极性的，并且与极性溶剂的相互作用较弱。

2.In polar molecules, the dipole moment indicates the direction of the electric field created by the separation of charges.

在极性分子中，偶极矩指示了由电荷分离产生的电场方向。

3.Chemists often use dipole moment calculations to predict molecular interactions in solvents.

化学家常用偶极矩计算来预测溶剂中的分子相互作用。

4.The dipole moment of ammonia is higher than that of methane, which explains why ammonia is more soluble in water.

氨的偶极矩高于甲烷，这解释了氨为何在水中更易溶解。

5.The water molecule has a significant dipole moment, which contributes to its unique properties such as high surface tension.

水分子具有显著的偶极矩，这使其具有高表面张力等独特性质。

作文

The concept of dipole moment is fundamental in the study of molecular chemistry and physics. It refers to a measure of the separation of positive and negative charges within a molecule. When we think about molecules, we often picture them as simple structures, but in reality, they can be quite complex. The dipole moment quantifies how polar a molecule is, which directly influences its physical properties such as boiling points, solubility, and interactions with other molecules.To understand dipole moment, we first need to grasp the idea of polarity in molecules. A molecule is considered polar when there is an uneven distribution of electron density. This occurs when atoms in a molecule have different electronegativities, which is the tendency of an atom to attract electrons. For instance, in a water molecule (H₂O), oxygen is more electronegative than hydrogen. As a result, the electrons spend more time closer to the oxygen atom, creating a partial negative charge on the oxygen and a partial positive charge on the hydrogens. This separation of charges leads to the formation of a dipole moment.The dipole moment is a vector quantity, meaning it has both magnitude and direction. The magnitude indicates the strength of the dipole, while the direction points from the positive charge to the negative charge. Mathematically, the dipole moment (often represented by the symbol 'p') can be calculated using the formula:

where 'q' is the charge and 'd' is the distance between the charges. The unit of dipole moment is the Debye (D), where 1 D is approximately equal to 3.336 × 10⁻³⁰ coulomb-meters.Understanding the dipole moment is crucial in predicting how molecules will behave in different environments. For example, molecules with high dipole moments tend to be more soluble in polar solvents like water, while nonpolar molecules with low or zero dipole moments are more soluble in nonpolar solvents like hexane. This principle is essential in fields like biochemistry and pharmacology, where the solubility of compounds can determine their effectiveness as drugs.Additionally, the dipole moment plays a significant role in intermolecular forces. Molecules with permanent dipole moments can engage in dipole-dipole interactions, which are attractive forces between the positive end of one polar molecule and the negative end of another. This interaction is stronger than London dispersion forces, which occur in nonpolar molecules, and can significantly affect the boiling and melting points of substances.In conclusion, the dipole moment is a critical parameter that helps chemists and physicists understand the behavior of molecules. By analyzing the dipole moment, scientists can predict the physical properties of substances, their solubility, and their interactions with other molecules. As we continue to explore the molecular world, the significance of the dipole moment will only grow, highlighting the intricate dance of charges that govern chemical behavior.In summary, the dipole moment serves as a bridge connecting molecular structure to physical properties, making it an indispensable concept in the scientific community.

概念偶极矩在分子化学和物理学的研究中是基础性的。它指的是分子内正负电荷分离的量度。当我们考虑分子时，常常会将其视为简单的结构，但实际上，它们可以相当复杂。偶极矩量化了分子的极性程度，这直接影响其物理性质，如沸点、溶解度以及与其他分子的相互作用。要理解偶极矩，我们首先需要掌握分子极性的概念。当分子内电子密度分布不均时，分子被认为是极性的。这种情况发生在分子中的原子具有不同的电负性时，电负性是原子吸引电子的趋势。例如，在水分子（H₂O）中，氧的电负性高于氢。因此，电子更倾向于靠近氧原子，这导致氧带有部分负电荷，而氢则带有部分正电荷。这种电荷的分离导致了偶极矩的形成。偶极矩是一个矢量量，意味着它既有大小也有方向。大小表示偶极的强度，而方向则指向从正电荷到负电荷的方向。从数学上讲，偶极矩（通常用符号'p'表示）可以通过以下公式计算：

其中'q'是电荷，'d'是电荷之间的距离。偶极矩的单位是德拜（D），1 D大约等于3.336 × 10⁻³⁰库伦·米。理解偶极矩对预测分子在不同环境中的行为至关重要。例如，具有高偶极矩的分子往往在极性溶剂如水中更易溶解，而低或零偶极矩的非极性分子则更易溶解于非极性溶剂如己烷。这一原则在生物化学和药理学等领域中至关重要，因为化合物的溶解度可以决定其作为药物的有效性。此外，偶极矩在分子间力中也扮演着重要角色。具有永久偶极矩的分子可以进行偶极-偶极相互作用，这是一个极性分子之间正端和负端之间的吸引力。这种相互作用比发生在非极性分子中的伦敦色散力更强，可以显著影响物质的沸点和熔点。总之，偶极矩是一个关键参数，帮助化学家和物理学家理解分子的行为。通过分析偶极矩，科学家可以预测物质的物理性质、溶解度及其与其他分子的相互作用。随着我们继续探索分子世界，偶极矩的重要性只会增加，突显出支配化学行为的电荷之间错综复杂的舞蹈。总而言之，偶极矩作为连接分子结构与物理性质的桥梁，使其成为科学界不可或缺的概念。