Search results
Results From The WOW.Com Content Network
Valence shell electron pair repulsion (VSEPR) theory (/ ˈ v ɛ s p ər, v ə ˈ s ɛ p ər / VESP-ər, [1]: 410 və-SEP-ər [2]) is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. [3]
Structure and properties Index of refraction, n D: 1.41156 at 25 °C Abbe number? Dielectric constant, ε r: 2.248 ε 0 at 0 °C Bond strength: 381 kJ/mol (Si-Cl) Bond length? Bond angle: 109° (Cl-Si-Cl) Dipole#Molecular dipoles: 0 D Magnetic susceptibility: −87.5 Viscosity: 99.4 mPa.s at 25 °C 96.2 mPa.s at 50 °C Thermal conductivity
Like other chlorosilanes or silanes, silicon tetrachloride reacts readily with water: . SiCl 4 + 2 H 2 O → SiO 2 + 4 HCl. The reaction can be noticed on exposure of the liquid to air, as SiCl 4 vapour produces fumes as it reacts with moisture to give a cloud-like aerosol of silica and hydrochloric acid. [6]
Molecular geometry is the three-dimensional arrangement of the atoms that constitute a molecule. It includes the general shape of the molecule as well as bond lengths , bond angles , torsional angles and any other geometrical parameters that determine the position of each atom.
Nonlinear geometry is commonly observed for other triatomic molecules and ions containing only main group elements, prominent examples being nitrogen dioxide (NO 2), sulfur dichloride (SCl 2), and methylene (CH 2). This geometry is almost always consistent with VSEPR theory, which usually explains non-collinearity of atoms with a presence of ...
According to the VSEPR theory of molecular geometry, an axial position is more crowded because an axial atom has three neighboring equatorial atoms (on the same central atom) at a 90° bond angle, whereas an equatorial atom has only two neighboring axial atoms at a 90° bond angle. For molecules with five identical ligands, the axial bond ...
This would result in the geometry of a regular tetrahedron with each bond angle equal to arccos(− 1 / 3 ) ≈ 109.5°. However, the three hydrogen atoms are repelled by the electron lone pair in a way that the geometry is distorted to a trigonal pyramid (regular 3-sided pyramid) with bond angles of 107°.
According to VSEPR theory, diethyl ether, methanol, water and oxygen difluoride should all have a bond angle of 109.5 o. [12] Using VSEPR theory, all these molecules should have the same bond angle because they have the same "bent" shape. [12] Yet, clearly the bond angles between all these molecules deviate from their ideal geometries in ...