On the contradiction between the hybrid orbital theory and the valence shell electron pair mutual ex

According to the valence shell electron repulsion theory, the number of valence electrons in clo2 = 5, the number of lone pairs = 3 Oops, you should memorize the table of the valence shell electron repulsion theory, it is very good to memorize.

Let's give you a connection.

Compounds with valence electron number = 3 and lone pair electron number = 1" correspond to V-type.

The number of valence electrons = 4 and the number of lone pairs = 2" are also v-shaped with h20

ClO2 is sp2 hybridized and is not a linear V-shaped lone electron pair occupying a hybrid orbital.

There is also a delocalized bond present in the molecule perpendicular to the molecular plane.

The lone electron is not involved in hybridization and is not sp3

NH3: According to the valence shell electron pair mutual exclusion model, the number of valence electrons of one n and three h is 8, the mutual exclusion model is ax3e1 (a represents the central atom, x represents the coordination atom, e represents the lone pair, 2*3+2*1=8), the mutual exclusion number z=3+1=4, so it is a regular tetrahedral configuration, only considering the coordination atom and the central atom is the trigonal pyramidal configuration, but because the repulsion of the lone pair to the single bond is greater than the repulsion of the single bond to the single bond, the h-n-h angle is more than the ideal case (109°28') small, measured at 107°18;

According to the hybrid orbital theory, the n atom adopts sp3 hybridization, and the configuration is the same as that of the valence shell electron pair mutual exclusion model.

BF3: According to the valence shell electron pair mutual exclusion model, the number of valence electrons of one b and three f is 24, and the mutual exclusion model is ax3e0 (a represents the central atom, x represents the coordination atom, e represents the lone pair, 8*3+2*0=8, note that h in nh3 is special 2-electron stable, and f is 8-electron stable), the mutual exclusion number z=3+0=3, so it is a standard planar triangular configuration, and the bond angle is 120 degrees;

According to the hybrid orbital theory, the B atom is hybridized with sp2, and the configuration is the same as that of the valence shell electron pair mutual exclusion model.

ps: The sp4 hybridization upstairs really blinded me.

The orbital hybrid theory refers to the atomic orbital hybrid theory. We know that the electrons outside the nucleus of an atom are arranged on atomic orbitals of different energy levels, such as s orbitals, p orbitals, etc., when atoms form molecules, in order to enhance the bonding ability (so that the lowest energy after bonding is the most stable), different types of atomic orbitals with similar energy in the same atom are recombined to form new atomic orbitals with different energy, shape and direction from the original orbital (the energy of this orbital is lower than the energy before there is no hybridization).For example, sp hybridization, sp2 hybridization, etc., this process of recombination of atomic orbitals is called the hybridization of atomic orbitals, and the new atomic orbitals formed are called hybrid orbitals.

After the formation of hybrid orbitals, the energy of the whole molecule is reduced by the combination of other atoms, and a stable state is reached.

Valence shell electron repulsion theory is mainly used to explain the theory of the spatial structure of some molecules, in addition to considering the spatial structure of a molecule (polyatomic) in addition to considering the relationship between the size and arrangement of its constituent atoms, it is better to take into account the lone electron pairs of the central atom, which has a repulsive effect on other atoms, so that the molecule or atomic cluster has a different spatial structure. What planar type, triangular pyramid and so on. It can be calculated with a formula, but I guess you won't learn that deeply.

As for the main points of molecular orbital theory, there are the following three points: First, after the atom forms a molecule, the electron is no longer limited to the atomic orbital of the individual atom, but is subordinate to the molecular orbital of the whole molecule. Therefore, molecular orbitals emphasize the integrity of molecules, in other words, after the formation of molecules, we cannot consider them in isolation one atom at a time, and electrons must also be considered in the molecular orbitals they form, and we can no longer use what atoms are arranged in the outer shell of electrons.

Second, the distribution of electrons in molecular orbitals is also the same as the distribution of electrons in atoms, following Pauli's principle of incompatibility (at most two electrons in a molecular orbital), the principle of lowest energy (according to the arrangement, the energy should be the lowest, and you will learn the knowledge of antibond orbitals in college, etc., then you will know why the energy is the lowest), and Hunt's rule (the electrons of an orbital should spin in the opposite direction, which is related to the spin quantum number of the orbital, which will be learned in "Structural Chemistry" in the future).In molecular orbitals, electrons can be paired or unpaired (after the formation of molecules there will be spin single electrons, they are not paired, all molecules that will have paramagnetism and diamagnetism).Thirdly, molecular orbitals can be obtained approximately through the linear combination of atomic orbitals, such as s orbitals and s orbitals to form molecular orbitals.

The number of molecular orbitals is equal to the sum of the number of atomic orbitals before combination.

Classmate, although I have been working hard for so long, I guess not only did I not help you, but I made you even more confused. It is recommended that you take a good look at your textbook, which may be simpler. I always say that high school shouldn't be so hard!

I really don't know what those people who make textbooks want to do, but I will definitely change them when I compile them!

1) Explain the geometric configuration of molecules, and both the hybrid orbital theory and the valence shell electron pair repulsion theory can explain the geometric configuration of molecules. For example, to explain the tetrahedral configuration of CH4, according to the hybrid orbital theory, C adopts sp3 isosexual hybridization, and the tetrahedral distribution of the four hybrid orbitals makes CH4 have a tetrahedral configuration. According to the theory of valence shell electron pair repulsion, the C valence shell has 4 electron pairs, and the valence shell electron pairs are tetrahedral distributed, and the number of electron pairs is the same as the number of ligands, so that CH4 has a tetrahedral configuration. The valence shell electron pair repulsion ridge theory determines the geometric configuration of a molecule based on the number of electron logarithms and the electron pair configuration, while the hybrid orbital theory explains the geometric configuration of the molecule and explains the formation process of this configuration.

2) The correspondence between the orbital hybrid type and the electron pair configurationThe central valence layer electric tomono reciprocal logarithm generally corresponds to the hybrid type of the orbital, that is, the electron pair configuration corresponds to the hybrid type of the orbital. The valence shell electron pair repulsion theory can first be used to determine the valence shell electron pair number or electron pair configuration of the central atom, and then the hybrid type of the central atom, such as 2 pairs of electrons, linear and sp hybridization. 3 pairs of electrons, regular triangle, sp2 hybrid; 4 pairs of electrons, tetrahedral, sp3 hybridized; 5 electron, trigonal bipyramidal, sp3d hybridized; 6 pairs of electrons, octahedral, sp3d2 hybrid. The exception is that CIO2 has 4 pairs of electrons, but Cl adopts sp2 hybridization instead of sp3 hybridization (which is not discussed in detail here).

3) The relationship between lone electron pairs and hybridization typeIf the number of ligands is equal to the number of valence shell electron pairs, and there are no lone good positron pairs in the molecule, the central atom adopts equal hybridization, such as BCL3, SO3 and PF5 molecules; If the number of ligands is less than the number of valence shell electron pairs, and there are lone electron pairs in the molecule, the central atom adopts unequal hybridization, as in the H2O, NH3, and SF4 molecules. If it is an equitropic hybrid, the distribution of hybrid orbitals is consistent with the molecular configuration. In the case of unequal hybridization, the lone electron pair occupies the hybrid orbital but does not act as the vertex, and after determining the position of the lone electron pair, the remaining hybrid orbital bonds with the ligand, and the structure of the molecule can be determined. Valence shell orbital electrons that are not involved in hybridization, generally form bonds or delocalized bonds.

O3(-) One oxygen is the central ion, and the other two oxygen are coordination atoms, so according to the valence shell electron pair repulsion theory, the number of paired electrons = (6+1) 2=

Therefore, the central ion oxygen is sp3 hybridized, and the electronic space structure is tetrahedral shaped.

However, since two orbitals are occupied by electrons (one orbital occupies two electrons and the other orbital occupies one electron), the spatial configuration of the ozone molecule is V-shaped, and the hybrid type is sp3 unequal hybridization.