Shapes of Molecules. Electron Pair Repulsions Electron pairs are negatively charged, they repel each other and therefore like to get as far apart as possible.

Slides:

Advertisements

Similar presentations

VSPER Molecular shapes Valence Shell Electron Repulsion Theory.

Advertisements

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)

1 Chapter 10 Molecular Structure: Solids and Liquids 10.3 Shapes of Molecules and Ions (VSEPR Theory) Copyright © 2008 by Pearson Education, Inc. Publishing.

Chapter 9 Molecular Geometry and Bonding Theories.

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.

Advanced Higher Chemistry Unit 1 Shapes of molecules and polyatomic ions.

Drawing Lewis Structures and VSEPR A Tutorial on Writing Lewis Dot Structure.

Molecular Geometry (Shapes of Molecules)

Shapes of molecules & ions. VSEPR theory VSEPR - the Valence Shell Electron Pair Repulsion theory is used to obtain the shape of simple molecules and.

VSEPR Theory Valence Shell Electron Pair Repulsion.

Molecular Shape Section 9.4

Shapes of molecules 1) sketch the Lewis structure 2) locate the central atom 3) count regions of electron density around the central atom double/triple.

Shapes of molecules. How to predict the shapes of molecules Shapes can be predicted from the number of electron pairs around the central atom of a molecule.

Shapes of molecules  The shapes of molecules and ions can be described by valence shell electron pair repulsion  VSEPR predicts the shapes and bond.

IIIIII Molecular Geometry Molecular Structure. A. VSEPR Theory  Valence Shell Electron Pair Repulsion Theory  Electron pairs orient themselves so that.

Cornell Notes (Section 8.4, especially page 263  Topic: Molecular Geometry  Date: 2/7/2012  VSEPR = Valence Shell Electron Pair Repulsion  Valence.

Molecular Shapes If you were to draw the Lewis structure for Carbon tetrachloride based on what you have already taken in this class, you may come up with.

Valence Shell Electron Pair Repulsion Theory (4.3 of textbook)

VSEPR. This is the shape that CO 2 makes. 1. Linear 2. Bent 3. Trigonal planar 4. Tetrahedral 5. Trigonal pyramidal 6. Trigonal bipyramidal 7. See-saw.

VSEPR Theory Valence Shell Electron Pair Repulsion.

Molecular Shapes Chapter 6 Section 3. Lewis dot structures show how atoms are bonded together, but they often do not illustrate the true shape of a molecule.

VSEPR Theory Valence Shell Electron Pair Repulsion.

Molecular Geometry and VSEPR Theory

Valence Shell Electron Pair Repulsion Theory

Objectives for Bonding and Periodicity (2)

Molecular Geometry and Bonding Theories.

Molecular Geometry VSEPR.

Ch.14 Covalent Bonding Hybridization.

Molecular Geometry VSEPR Theory- “Valence- shell, electron-pair repulsion” states that repulsion between the sets of valence-level electrons surrounding.

Arrangement of Two Electron Pairs on Be

Valence Shell Electron Pair Repulsion Theory

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

Timberlake LecturePLUS

VSEPR Pronounced vesper…a vespa for her A vest purrs???

ValenceShellElectronPairRepulsion

Ch. 6 – Molecular Structure

Valence Shell Electron Pair Repulsion Theory

Valence Shell Electron Pair Repulsion Theory

Ch. 6.5 Bonding Theories Molecular Geometry.

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

Valence Shell Electron Pair Repulsion

MOLECULAR GEOMETRY Bonding Unit.

II. Molecular Geometry (p. 183 – 187)

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

Ch. 6 – Molecular Structure

Molecular Geometry and VSEPR Theory

Molecular Shape & Geometry

Important Information:

Molecular Structure Molecular Geometry.

Molecular Geometry and VSEPR Theory

GEOMETRY AND POLARITY OF MOLECULES

Valence Shell Electron Pair Repulsion Theory

Valence Shell Electron Pair Repulsion

Chapter 10 Properties of Solids and Liquids

Molecular Geometry VSEPR Theory- “Valence- shell, electron-pair repulsion” states that repulsion between the sets of valence-level electrons surrounding.

Valence Shell Electron Pair Repulsion Theory

Valence Shell Electron Pair Repulsion Theory

VSEPR & Geometry Lewis structures show the number and type of bonds between atoms in a molecule or polyatomic ion. Lewis structures are not intended to.

5.1 Molecular Shape Obj 1 Chemistry.

Explain what the VSEPR Theory is

Molecular Structure II. Molecular Geometry.

II. Molecular Geometry (p. 183 – 187)

Molecular Shapes VSEPR Model

6.5 VSEPR Theory and Molecular Shapes

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 Theory

Presentation transcript:

Shapes of Molecules

Electron Pair Repulsions Electron pairs are negatively charged, they repel each other and therefore like to get as far apart as possible. Using molymod kits build a structure to represent methane (CH 4 ), what do you think is the angle between the bonding pairs?

Tetrahedral When there are 4 bonding pairs (BPs) of electrons around the central atom they adopt a ‘Tetrahedral’ shape. The bond angle is approximately 109 ◦ This is represented by:

Drawing 3D Structures »Represents a bond in the plane of the paper. »Represents a bond in a direction behind the plane of the paper. »Represents a bond in a direction in front of the plane of the paper.

What about lone pairs? Lone pairs also repel against the bonding pairs. In fact their repulsion is even stronger! Try making structures for Ammonia (NH 3 ) and Water (H 2 O) How would you describe the shapes and bond angles?

Water and Ammonia Ammonia’s 3 bonding pairs and lone pair adopt similar positions to 4 bonding pairs in methane. Bond Angle = ~109 ◦ Name = Pyramidal Water has 2 lone pairs and 2 boning pairs and again they adopt positions similar to methane. Bond Angle = ~109 ◦ Name = Bent

Linear Molecules When there are only two groups around the central atom they will get as far apart as possible. Name = Linear Bond Angle = 180 ◦ E.g. BeCl 2 and CO 2

Planar Molecules When there are three groups of electrons around the central atom the furthest they can get apart is 120 ◦ Name = Trigonal Planar Bond angle = 120 ◦ E.g. BF 3, methanal and ethene

Trigonal Bipyramidal Molecules This is where there are 5 groups of bonding electrons. It is like trigonal planar but with two extra groups of electrons occupying spaces above and below the plane. Name = Trigonal bipyramidal Bond angle = 120° or 90 ° E.g. PCl 5

Octahedral This is where 6 groups of bonding electrons surround a central atom, it is similar to trigonal bipyramidal apart from having an extra group of electrons in the central plane. Name = Octahedral Bond Angle = 90° E.g. SF 6

Shapes of ions You can use the same principles to determine the shapes of ions by looking at how many electrons have been gained or lost. E.g. NH 4 + AmmoniaNH 2 - TetrahedralPyramidalBent 4xBP 3xBP and 1xLP 2xBP and 2xLP

Now you try… Now have a go at 3.2 Problems 1-3 before attempting the ‘Balloon Challenge’.