University Chemistry ›› 2022, Vol. 37 ›› Issue (6): 2107112.doi: 10.3866/PKU.DXHX202107112

• Self Studies • Previous Articles     Next Articles

The Simplified Method for Calculating the Number of Valence Shell Electron Pairs and Application of the VSEPR Theory

Wei Zhang(), Li Ma, Shaoai Xie, Yuling Wang, Hongjin Chen   

  • Received:2021-07-31 Accepted:2021-09-10 Published:2021-11-04
  • Contact: Wei Zhang E-mail:weizhang@sjtu.edu.cn

Abstract:

Aiming at the unspecified problem that the number of electrons provided by a halogen, oxygen group, and other p-group non-metallic elements as coordination atoms is 1, 0 etc. in VSEPR theory, this article focuses on explaining the numbers using mathematical formula and presents a simplified method for calculating the valence electron pairs using calculation rules for the central and coordination atoms. This article specifically presents a new method to analyze the hybrid type of organic small molecules with a chain structure using the deducted calculation rules. Furthermore, it discusses how the outermost s-electrons of the long-period p-group non-metallic elements impact the total number of valence electrons via the penetration effect and the mutual influence of multiple bonds to compare the bond angles of covalent molecules using the differences in the electronegativity. This method is expected to be a useful supplement to the application of VSEPR theory.

Key words: VSEPR, Valence electron pairs, Hybrid type, Bond angle

MSC2000: 

  • G64