From a735d09aefcb83feea20910ac5464725d72c56c1 Mon Sep 17 00:00:00 2001 From: eggy Date: Tue, 10 Nov 2020 14:25:52 -0500 Subject: [PATCH] chem: finish vsepr --- docs/sch3uz.md | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/docs/sch3uz.md b/docs/sch3uz.md index 63d6fcf..6316be0 100644 --- a/docs/sch3uz.md +++ b/docs/sch3uz.md @@ -666,6 +666,7 @@ A **3D diagram** of a molecule is drawn similarly to three-dimensional Lewis str - 90° angles are only present in molecules with five electron domains, and should be avoided in all other scenarios. - The angle between the peripheral atoms should be labelled once for each distinct angle. - for $\text{AX}_n\text{E}_m$ structures, where $n+m=4$, the angle between peripheral atoms is equal to $109.5° - 2.5m$. + - for $\text{AX}_n\text{E}_m$ structures, where $n+m=3$, the angle between peripheral atom is equal to $120°-3m$. !!! example The below 3D diagrams are for $\text{CH}_4$, $\text{NH}_3$, and $\text{H}_2\text{O}$, respectively. Note that the angle on $\text{NH}_3$ is supposed to be $107°$. @@ -679,16 +680,16 @@ Because of the addition of d orbitals beginning from $n=3$, elements in period 3 In molecules with 5 or 6 electron domains, their electron distribution is as follows, respectively: (Source: Kognity) -In a trigonal bipyramid, the **equatorial** positions of domains refer to the position of the domains on the x- and z-dimensions (a trigonal plane). The domains along the y-dimension are have **axial** positions. The angle between the two is known as the **equatorial-axial** angle. Lone pairs are always placed in equatorial positions. +In a trigonal bipyramidal, the **equatorial** positions of domains refer to the position of the domains on the x- and z-dimensions (a trigonal plane). The domains along the y-dimension are have **axial** positions. The angle between the two is known as the **equatorial-axial** angle. Lone pairs are always placed in equatorial positions. | AXE | Electron distribution | Molecular shape | Bond angle | | --- | --- | --- | --- | | $\text{AX}_5$ | trigonal bipyramidal | trigonal bipyramidal | equatorial=120°, equatorial-axial=90° | -| $\text{AX}_4\text{E}$ | trigonal bipyramidal | see-saw | | -| $\text{AX}_3\text{E}_2$ | trigonal bipyramidal | t-shaped | | +| $\text{AX}_4\text{E}$ | trigonal bipyramidal | see-saw | equatorial=117°, equatorial-axial=90° | +| $\text{AX}_3\text{E}_2$ | trigonal bipyramidal | t-shaped | equatorial-axial=90° | | $\text{AX}_2\text{E}_3$ | trigonal bipyramidal | linear | 180° | | $\text{AX}_6$ | octahedral | octahedral | 90° | -| $\text{AX}_5\text{E}_6$ | octahedral | square pyramidal | | +| $\text{AX}_5\text{E}_6$ | octahedral | square-based pyramidal | 88.5° | | $\text{AX}_4\text{E}_2$ | octahedral | square planar | 90° | !!! example