CHE 106 Lecture Notes - Lecture 20: Molecular Orbital Theory, Valence Bond Theory, Vsepr Theory

38 views8 pages

orangegoldfish942

14 Nov 2017

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

kazasrikar and 38298 others unlocked

CHE 106 Full Course Notes

Verified Note

63 documents

Document Summary

The shape of molecules is critical to their function. Shape is important in both small and large molecules. The three-dimensional arrangement of the atoms that constitute a molecule. Valence bond theory : assumes that all bonds are localized bonds formed between two atoms by the donation of an electron from each atom. this is actually an invalid assumption because many atoms bond using delocalized electrons. Molecular orbital theory : a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole molecule. Electron pairs : consists of two electrons that occupy the same orbital but have opposite spins. Electron domains/regions : the number of lone pairs or bond locations around a particular atom in a molecule. Used to predict the geometry of molecules based on minimizing the electrostatic repulsion of a molecule"s valence electrons around a central atom.

Related Questions

Predict the molecular shape of using VSEPR theory.

Draw for yourself the best Lewis structure.
Count the number of electron groups (bond pairs and lone pairs, with multiple counting as one effective electron group) around the central atom, Answer

To establish the electron-group arrangement, Answer. From the electron-group arrangement, you can determine the hybridization of the central atom to be Answer

The electron-group arrangement is not (necessarily) the same as the molecular shape, which is named on the basis of the arrangement of atoms. The molecular shape is Answer
The ideal bond angles around the central atom are Answer. By analyzing repulsive forces between electron pairs (both lone pairs and bond pairs) and realizing that only bond angles subtended by atoms (not lone pairs) can actually be observed, you can predict if any deviations will occur; the experimental bond angles around the central atom will be Answer the ideal bond angles.
Taking the vector sum of bond dipoles, you can evaluate the net dipole moment and predict that the molecule will be Answer