Its All about Pj Problem Strings (SiPjAjk) - 7 Spaces Of Interest (Si) and their associated Basic Sequences; 7 Pj Problems of Interest (PPI) and their Alleles (Ajk)

Expressions Of Pj Problems.

Pj Problems - Overview
Celestial Stars As Expressions Of Pj Problems
The Number Line As Expression Of Pj Problems
Geometries As Expressions Of Pj Problems
7 Spaces Of Interest - Overview
Triadic Unit Mesh
Creation As Expression Of Pj Problems
The Atom As Expression Of Pj Problems
Survival As Expression Of Pj Problems
Energy As Expression Of Pj Problems
Light As Expression Of Pj Problems
Heat As Expression Of Pj Problems
Sound As Expression Of Pj Problems
Music As Expression Of Pj Problems
Language As Expression of Pj Problems
Stories As Expressions of Pj Problems
Work As Expression Of Pj Problems
States Of Matter As Expressions Of Pj Problems
Buoyancy As Expression Of Pj Problems
Nuclear Reactions As Expressions Of Pj Problems
Molecular Shapes As Expressions Of Pj Problems
Electron Configurations As Expressions Of Pj Problems
Chemical Bonds As Expressions Of Pj Problems
Energy Conversion As Expression Of Pj Problems
Chemical Reactions As Expressions Of Pj Problems
Electromagnetism As Expression Of Pj Problems
Continuity As Expression Of Pj Problems
Growth As Expression Of Pj Problems
Human-cells As Expressions Of Pj Problems
Proteins As Expressions Of Pj Problems
Nucleic Acids As Expressions Of Pj Problems
COHN - Nature's Engineering Of The Human Body
The Human-Body Systems As Expressions Of Pj Problems
Vision As Expression Of Pj Problems
Walking As Expression Of Pj Problems
Behaviors As Expressions Of Pj Problems
Sensors' Sensings As Expressions Of Pj Problems
Beauty As Expression Of Pj Problems
Faith, Love, Charity As Expressions Of Pj Problems
Photosynthesis As Expressions Of Pj Problems
Weather As Expression Of Pj Problems
Systems As Expressions Of Pj Problems
Algorithms As Expressions Of Pj Problems
Tools As Expressions Of Pj Problems
Networks As Expressions Of Pj Problems
Search As Expressions Of Pj Problems
Differential Calculus As Expression Of Pj Problems
Antiderivative As Expression Of Pj Problems
Integral Calculus As Expression Of Pj Problems
Economies As Expresions Of Pj Problems
Inflation As Expression Of Pj Problems
Markets As Expressions Of Pj Problems
Money Supply As Expression Of Pj Problems
Painting As Expressions Of Pj Problems
Predicting Molecular Shape With The VSEPR Model

Precise molecular shapes are determined by the bond lengths and bond angles established by the bonding atoms. However, the Valence Shell Electron Pair Repulsion (VSEPR) model predicts molecular shapes fairly well. Here, we examine VSEPR as it relates to the prediction of molecular shapes of AB molecules.

1. Define the following: (a) ABn molecules (b) Lewis Electron-Dot Diagram (c) Electron Domain.
2. Determine the Lewis structure for the following molecules: (a) CO2 (b) H2O (c) BF3 (d) XeF4 (e) CCl4 (f) NH3 (g) PCl5 (h) SF6
3. Use the Valence-Shell Electron-Pair Reduction (VSEPR) model to predict the molecular shapes and bond angles of the molecules indicated in problems 2a, 2c, 2e, 2g and 2h.
4. Predict the molecular geometries of the molecules of 2b, 2d and 2f, from the electron-domain geometries of problem 2. Will the bond angles of these molecules be greater or smaller than the bond angles indicated in the electron-domain geometries from which their molecular geometries were derived?
5. Write a general representative string for the VSEPR model.

1(a) ABn molecules are molecules with a central atom (A) and n similar atoms (B) bonded to A. For example CO2 (where carbon is the A atom and oxygen the B atoms with n =2).
1(b) The Lewis Dot Diagram is the representation of an atom, ion, or molecule such that the element's symbol represents the nucleus and all inner shell electrons while the dots that surround the symbol represent the valence electrons. The diagram is also called the Lewis structure of the atom, ion or molecule.
1(c) Electron domain refers to the region occupied by non-bonding pair of electrons, a single covalent bond, or multiple covalent bonds around the central atom of an ABn molecule.

2. The Lewis structures for the molecules are:
Lewis Electron Dot Diagram

3. The general steps for using the VSEPR model is as follows:
(i). Determine the Lewis structure of the molecule or ion, then count the total electron-domains around the central atom. Each nonbonding pair, single bond, or multiple bond around the central atom counts as an electron-domain.
(ii). Determine the electron-domain geometry by arranging the electron-domains about the central atom in a manner that minimizes the electron repulsion among them.
(iii). Use the arrangement of the bonded atoms to determine the molecular geometry of the molecules.
CO2:
Molecular Geometry CO2
Electron domains = 2; bonding domains = 2; nonbonding domains = 0; electron geometry = linear; molecular geometry = linear; bonding angle = 180o
BF3:
Molecular Geometry BF<sub>3</sub>
Electron domains = 3; bonding domains = 3; nonbonding domains = 0; electron geometry = trigonal planar; molecular geometry = trigonal planar; bonding angle =120o. In the trigonal planar, all the atoms are on the same triangular plane of an equilateral triangle.
CCl4:
Molecular Geometry CCl<sub>4</sub>
Electron domains = 4; bonding domains = 4; nonbonding domains = 0; electron geometry = tetrahedral; molecular geometry = tetrahedral; bonding angle = 109.5o. The tetrahedron has 4 vertices and four faces all of which are equilateral triangles. The vertices of the equilateral base holds three atoms. The central atom is the center of the tetrahedron which is above the plane of the base. The fourth atom is at the fourth vertex which is above both the base of the tetrahedron and the central plane.
PCl5:
Molecular Geometry PCl<sub>5</sub>
Electron domains = 5; bonding domains = 5; nonbonding domains = 0; electron geometry = trigonal bipyramidal; molecular geometry = trigonal bipyramidal; bonding angle between axial and equatorial bond = 90o; bond angle between equatorial bonds = 120o. The trigonal bipyramid has 5 vertices. Three of which are the vertices of an equilateral triangle. The three atoms at the vertices of the equilateral triangle are equatorial atoms. The central atom A, is at the center of the equilateral triangle. The two atoms at the vertices above and below the plane of the equilateral triangle are axial atoms.
SF6:
Molecular Geometry SF<sub>6</sub>.
Electron domains = 6; bonding domains = 6; nonbonding domains = 0; electron geometry = octahedral; molecular geometry = octahedral; bonding angle between axial and equatorial bond = 90o; bond angle between equatorial bonds = 90o. The octahedral has six vertices and 8 surfaces which are all equilateral triangles. Four equatorial atoms are at the vertices of a square. The central atom A, is at the center of the square. The axial atoms are at the vertices above and below the plane of the square.

4. H20:
electron domains = 4; bonding domains = 2; nonbonding domains = 2; electron geometry = tetrahedral; molecular geometry = bent (tetrahedral minus 2 electron domains); bond angle will be less than 120o because of the effect of the nonbonding domains.
XeF4:
electron domains = 6; bonding domains = 4; nonbonding domains = 2; electron geometry = octahedral; molecular geometry = square planar (ocahedral minus 2 axial electron domains); bond angle 90o. No axial bonds.
NH3:
electron domains = 4; bonding domains = 3; nonbonding domains = 1; electron geometry = tetrahedral; molecular geometry = trigonal pyramidal (tetraahedral minus 1 electron domain); bond angle will be less than 120o because of the effect of the nonbonding domain.

5. The VSEPR model is based on repulsion so the general representative string is:
(S7P3A32)repulsion

Mind Warm Ups

The point "." is a mathematical abstraction. It has negligible size and a great sense of position. Consequently, it is front and center in abstract existential reasoning.

Problems by Peter O. Sagay

Conics

Ordinary Differential Equations (ODEs)

Vector Spaces

Real Numbers

What is Time?
St Augustine On Time
Bergson On Time
Heidegger On Time
Kant On Time
Sagay On Time
What is Space?
Newton On Space
Space Governance
Leaders
Imperfect Leaders
Essence Of Mathematics
Toolness Of Mathematics
The Number Line
Variables
Equations
Functions
The Windflower Saga
Who Am I?
Primordial Equilibrium
Primordial Care
Force Of Being
Forgiveness

Blessed are they that have not seen, and yet have believed. John 20:29

TECTechnic Logo, Kimberlee J. Benart | © 2000-2016 | All rights reserved | Founder and Site Programmer, Peter O. Sagay.