Intramolecular hydrogen bond formation process of nitric acid

The necessary condition for the formation of hydrogen bonds is that the bonds bound by hydrogen in the original molecule must be strong enough polarity, that is, the atoms bonded to hydrogen must have sufficient negative electricity, such as oxygen, fluorine, nitrogen, etc. Nitrogen and chlorine are almost equal in electroposivity, but nitrogen atoms are comparatively smaller and tend to form hydrogen bonds. For example, hydrogen bonding of water molecules.

Although hydrogen has been covalently bonded to oxygen in water molecules, due to the large negative electricity of oxygen, the electrons are strongly directed to one end of oxygen, so that hydrogen has a partial positive charge, and there is no covering electron outside this hydrogen nucleus, so it can also attract another negative element, that is, the oxygen of another water molecule, so that one or two water molecules are associated together, and the hydrogen atom has only one 1s electron, and it is impossible to form two covalent bonds, so h still maintains the covalent bond between it and oxygen in its original molecule, The oxygen of it and another water molecule is basically still electrostatic attraction, so the bond energy of the hydrogen bond is not large, only a few kilojoules. Due to the formation of hydrogen bonds, water molecules can be associated with three, four, five, or more together. Compounds with H-O, H-N, H-F and other bonds are easy to associate into associated molecules due to the formation of hydrogen bonds, which reduces their melting and boiling points, and reduces the heat of sublimation and vaporization, which also affects the solubility.

Hydrogen bonds can also be formed between different molecules, for example, organic amines and water can also be combined by hydrogen bonds, and ammonia and water can also form hydrogen bonds. The substances that can form hydrogen bonds are water, alcohols, amines, carboxylic acids, inorganic acids, hydrates, ammonia, etc., and proteins, fats, and sugars in the process of life contain hydrogen bonds, and hydrogen bonds are divided into two types: intramolecular hydrogen bonds and intermolecular hydrogen bonds.

I don't know the current concept, in the past, hydrogen bonds were only between molecules, not inside molecules.

Because the bond angle of hydrogen bonds formed in the molecular junction of nitric acid is smaller than that of acetic acid, it is easier to form intramolecular hydrogen bonds.

Nitric acid is an inorganic acid whose molecule is a planar covalent molecule and the hybrid form of the central nitrogen atom is sp2 hybrid. The hydroxyl group in nitric acid forms an intramolecular hydrogen bond with the non-hydroxylated oxygen atom, and the bond angle of this hydrogen bond O-N-OH is about 115 degrees.

As a common carboxylic acid, acetic acid may form intramolecular hydrogen bonds with a bond angle of 120 degrees and a more stable structure.

Neither acetaldehyde nor water can form intramolecular hydrogen bonds, and both intermolecular hydrogen bonds are possible.

The formation of intermolecular hydrogen bonds by H2O is well understood by everyone because everything that contains O-H bonds contains hydrogen bonds.

Acetaldehyde contains hydrogen bonds which may be a bit difficult to understand, just for the acetaldehyde molecule itself, there are only C-H bonds in the molecule, and there is no O-H, so it seems that hydrogen bonds cannot be formed; But acetaldehyde also has an isomer, enol formula: CH2=CHOH, which contains O-H bonds in this structure, so there will be hydrogen bonds; It's just that the proportion of the enol formula in acetaldehyde is very small, and the hydrogen bond is relatively weak, so the contribution of hydrogen bond is small.

But to make a judgment on the presence or absence of hydrogen bonds, it is better to say that there are.

1. Conditions for the formation of hydrogen bonds.

1. Hydrogen atoms that form strong polar bonds with atom A with great electronegativity 2, atoms b (f, o, n) with a small radius, large electronegativity, lone electron pairs, and partial negative charge

Intermolecular hydrogen bonding is usually more common.

2. Intramolecular hydrogen bonding:

Hydrogen bonding occurs within the same molecule.

1. In addition to the atoms that form hydrogen bonds (F, O, N connected to H) inside the molecule.

2. It must also be satisfied: the atoms that form hydrogen bonds can only be formed when they are in the right position. Hexagonal or pentagonal generation is usually best suited and is as close as possible to the same plane.

The o-c-o in the acetic acid molecule is V-shaped, and it is difficult to form intramolecular hydrogen bonds.

Hydrogen bonding is usually available for x-h....y to denote oak acres. Among them, X is connected to hydrogen by covalent bonds (or ionic bonds), which has high electronegativity, and can stabilize the negative charge, so hydrogen is easy to dissociate and has acidity (proton donor): hydrogen atoms are combined with electronegative atoms X with covalent bonds, and if they are close to the atom Y (O, F, N, etc.) with large negativity and small radius of Shennuclear power, hydrogen is used as the medium between X and Y to generate X-H....y-form of one.

h（+）no3(-)hno3

This is the ionic equation, and if you want the chemical equation, you need nitrate and weak acid. In the case of strong acids and nitrates, a reaction is required to produce water or gas or precipitation.

Within means + or — ions.