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London Dispersion Forces vs Hydrogen Bonds Strength
On the attraction between the dispersion force and the strength of the hydrogen bond
, there are two kinds of dispersion force and hydrogen bond. The strength of the dispersion force is quite important in the academic world.
The dispersion force originates from the interaction of the instantaneous dipole of the molecule. All molecules have electron clouds, and their distribution changes rapidly, resulting in the formation of instantaneous dipoles. This instantaneous dipole induces the formation of dipoles in neighboring molecules, resulting in a weak attraction between molecules, that is, the dispersion force. Although its force is weak, it is the main force between non-polar molecules and single-atom molecules.
The hydrogen bond is the interaction between a hydrogen atom and an atom with a large electronegativity and a small radius (such as fluorine, oxygen, nitrogen) when it is covalently bonded with another atom with a large electronegativity. The force of hydrogen bonding is stronger than that between ordinary molecules, and has a great influence on the properties of melting and boiling point and solubility of substances.
With common sense, the strength of hydrogen bonding is greater than the dispersion force. When capping hydrogen bonds are formed, hydrogen atoms are in a state of bare protons, attracting each other with electronegativity atoms, and their forces are stronger. The dispersion force is only caused by the instantaneous uneven distribution of electron clouds, and the force is weak.
Take water as an example. There are hydrogen bonds between water molecules, so the melting and boiling point of water is higher. If only the dispersion force exists, the melting and boiling point of water should be much lower than it is today. Another example is methane, which has only the dispersion force between molecules, and the melting and boiling point is very low.
However, there are also special cases. When the molecular weight is large and the electron cloud is easy to polarize, the dispersion force can be significantly enhanced. For example, iodine element, its intermolecular dispersion force is strong, and it is a solid state at room temperature. At this time, in iodine element, although the dispersion force is still not as strong as the hydrogen bond between water molecules, it makes it appear solid.
In summary, the hydrogen bond strength is usually stronger than the dispersion force, but the material characteristics are complex, and the dispersion force can also have a significant impact on the material properties under specific conditions. The strength of the two is compared, depending on the specific material and environment.
, there are two kinds of dispersion force and hydrogen bond. The strength of the dispersion force is quite important in the academic world.
The dispersion force originates from the interaction of the instantaneous dipole of the molecule. All molecules have electron clouds, and their distribution changes rapidly, resulting in the formation of instantaneous dipoles. This instantaneous dipole induces the formation of dipoles in neighboring molecules, resulting in a weak attraction between molecules, that is, the dispersion force. Although its force is weak, it is the main force between non-polar molecules and single-atom molecules.
The hydrogen bond is the interaction between a hydrogen atom and an atom with a large electronegativity and a small radius (such as fluorine, oxygen, nitrogen) when it is covalently bonded with another atom with a large electronegativity. The force of hydrogen bonding is stronger than that between ordinary molecules, and has a great influence on the properties of melting and boiling point and solubility of substances.
With common sense, the strength of hydrogen bonding is greater than the dispersion force. When capping hydrogen bonds are formed, hydrogen atoms are in a state of bare protons, attracting each other with electronegativity atoms, and their forces are stronger. The dispersion force is only caused by the instantaneous uneven distribution of electron clouds, and the force is weak.
Take water as an example. There are hydrogen bonds between water molecules, so the melting and boiling point of water is higher. If only the dispersion force exists, the melting and boiling point of water should be much lower than it is today. Another example is methane, which has only the dispersion force between molecules, and the melting and boiling point is very low.
However, there are also special cases. When the molecular weight is large and the electron cloud is easy to polarize, the dispersion force can be significantly enhanced. For example, iodine element, its intermolecular dispersion force is strong, and it is a solid state at room temperature. At this time, in iodine element, although the dispersion force is still not as strong as the hydrogen bond between water molecules, it makes it appear solid.
In summary, the hydrogen bond strength is usually stronger than the dispersion force, but the material characteristics are complex, and the dispersion force can also have a significant impact on the material properties under specific conditions. The strength of the two is compared, depending on the specific material and environment.
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