Molecular shapes.

Slides:

Advertisements

Similar presentations

Drawing Lewis structures

Advertisements

Molecular shapes Balls and sticks. Learning objectives  Apply VSEPR to predict electronic geometry and shapes of simple molecules  Distinguish between.

1 Shapes of Molecules Determined by number of valence electrons of the central atom 3-D shape a result of bonded pairs and lone pairs of electrons Use.

Basic Chemistry Copyright © 2011 Pearson Education, Inc. 1 Chapter 10 Structures of Solids and Liquids 10.2 Shapes of Molecules and Ions (VSEPR Theory)

Molecular shapes Balls and sticks. Learning objectives  Apply VSEPR to predict electronic geometry and shapes of simple molecules.

Molecular Shapes Chapter 6 Section 3. Molecular Structure It mean the 3-D arrangement of atoms in a molecule Lewis dot structures show how atoms are bonded.

Section 12.4 Structure of Molecules 1.To understand molecular structure and bond angles 2.To learn to predict molecular geometry from the number of electron.

B. Ionic bonding and Structures of Ionic Compounds

Molecular Shape VSEPR Model. Molecular Shape Physical/Chemical PROPERTIES SHAPE of Molecule (VSEPR) Overlap of ORBITALS (Hybridization)

Lewis Symbols and the Octet Rule Electron Dot Symbols convenient way of showing the valence electrons of atoms. Consists of the chemical symbol and one.

Molecular Shape and Polarity The Importance of Geometry in Determining Physical Properties.

Molecular shapes A simple matter of balls and sticks.

Molecular Geometry. 2-D and 3-D Lewis Structures explain the two dimensional structure of molecules In order to model the actual structure of a molecule.

Unit 3: Chemical Bonding

Chapter 9 Chemical Bonding

Review Double and Triple Bonds

Predict the geometry of the molecule from the electrostatic repulsions between the electron (bonding and nonbonding) pairs. Valence shell electron pair.

Chemistry Chapter 9 Notes #3. Representing Molecules Molecular Formula –Ex. CH 4 –Ex. H 2 O Structural/ Lewis Formula Ball & Stick Model Space Filling.

Chapter 12 Chemical Bonding. Chapter 12 Table of Contents 12.1 Types of Chemical Bonds (see Part 1) 12.2 Electronegativity (see Part 1) 12.3 Bond Polarity.

VSEPR Theory Valence Shell Electron Pair Repulsion.

Chapter 9 Molecular Shape.

6.8 Shapes and Polarity of Molecules

TOPIC: Molecular Geometry (Shapes of Molecules) Essential Question: How do you determine the different shapes of molecules?

Molecular Shape (Geometry)

Molecular Geometry (VSEPR)

Timberlake LecturePLUS

Molecular Geometries and Bonding Theories

Ch. 6 – Molecular Structure

Molecular Shapes.

Valence Shell Electron Pair

Electron Sharing can be EQUAL or UNEQUAL

Ch. 6.5 Bonding Theories Molecular Geometry.

“The shape of things to come”

Valence Shell Electron Pair Repulsion Theory (VSEPR)

Bellwork Monday Draw the following Lewis dot structures. CCl4 NH4+

Valence shell electron pair repulsion (VSEPR) model:

Valence Shell Electron Pair Repulsion

MOLECULAR GEOMETRY Bonding Unit.

II. Molecular Geometry (p. 183 – 187)

Molecular Geometry VSEPR and beyond!.

Chapter 6 – 3 Molecular Geometry (p. 214 – 218)

O = O V___________ S________ E________ P______ R____________

Ch. 6 – Molecular Structure

Chapter 8 Section 3 Molecular Structures.

Molecular Structure Molecular Geometry.

Molecular Geometry VSEPR Theory

GEOMETRY AND POLARITY OF MOLECULES

Chapter 10 Molecular Structure: Solids and Liquids

Valence Shell Electron Pair Repulsion

Molecular shapes Balls and sticks. Learning objectives  Apply VSEPR to predict electronic geometry and shapes of simple molecules  Distinguish between.

Chapter 10 Properties of Solids and Liquids

Molecular Geometry 11/8 Opener:

Molecular Structure and Shape

Objectives To understand molecular structure and bond angles

Unit 3: Chemical Bonding

Molecular Structure II. Molecular Geometry.

Molecular Geometry.

II. Molecular Geometry (p. 183 – 187)

Valence Shell electron pair repulsion model 3D models

Molecular Shapes It mean the 3-D arrangement of atoms in a molecule

Molecular Geometry.

Molecular Shapes VSEPR Model

Molecular Shapes Mrs. Chan.

Molecular Geometry.

Valence Shell Electron Pair Repulsion

II. Molecular Geometry (p. 183 – 187)

II. Molecular Geometry (p. 183 – 187)

Valence Shell Electron-pair Repulsion model

Valence Shell Electron Pair Repulsion (VSEPR) Theory

Presentation transcript:

Molecular shapes

Learning objectives Apply VSEPR to predict electronic geometry and shapes of simple molecules

Valence shell electron pair repulsion Lewis dot structure provides 2D sketch of the distribution of the valence electrons among bonds between atoms and lone pairs; it provides no information about molecular shape First approach to this problem is to consider repulsion between groups of electrons (charge clouds)

Electron groups (clouds) minimize potential energy Valence shell electron pair repulsion (VSEPR) Identify all groups of charge: non-bonding pairs or bonds (multiples count as one) Bonded atoms – single, double or triple count as 1 Lone pairs count as 1 Distribute them about central atom to minimize potential energy (maximum separation)

Total number of groups dictates electronic geometry Octet rule: Two – linear Three – trigonal planar Four – tetrahedral

Three groups: trigonal planar Two possibilities for central atoms with complete octets: Trigonal planar (H2CO) Bent (SO2) BCl3 provides example of trigonal planar with three single bonds B is satisfied with 6 electrons

Four groups: tetrahedral Three possibilities: No lone pairs (CH4) - tetrahedral One lone pair (NH3) – trigonal pyramid Two lone pairs (H2O) – bent Note: H-N-H angle 107° H-O-H angle 104.5° Tetrahedral angle 109.5°

Representations of the tetrahedron

Groups of charge Lone electron pairs Electronic geometry Molecular shape 2 Linear 3 Trigonal planar 1 Bent 4 Tetrahedral Trigonal pyramid

Two bonds Equal bonds oppose (linear) Unequal bonds oppose (linear) Nonpolar (CO2) Unequal bonds oppose (linear) Polar (HCN) Equal bonds do not oppose (bent) Polar (H2O)

Three bonds Equal bonds oppose in trigonal planar arrangement Nonpolar Unequal bonds in trigonal planar arrangement Polar