C has 4 valence electrons, O has six electrons. The total number of electrons is 4 + 2(6) = 16.

Size: px
Start display at page:

Download "C has 4 valence electrons, O has six electrons. The total number of electrons is 4 + 2(6) = 16."

Transcription

1 129 Lewis Structures G. N. Lewis hypothesized that electron pair bonds between unlike elements in the second (and sometimes the third) row occurred in a way that electrons were shared such that each element has an octet of electrons. Of course, hydrogen cannot have an octet. Look at HF, H 2 O, NH 3, CH 4 : In all of these systems, the heavy, central atom has eight electrons surrounding it. Let s also look at multiple bonding, as in CO 2 : C has 4 valence electrons, O has six electrons. The total number of electrons is 4 + 2(6) = 16. If each of the three atoms has a separate octet, 3(8) = 24 electrons would be required. Therefore = 8 electrons are shared in two bonds. Note that oxygen has two lone (unshared) pairs of electrons, carbon has none A more complicated system: O 3 : number of valence electrons is 6 per atom. 3(6) = 18 electrons If each atoms has a separate octet, then 24 electrons are required = 6 electrons to be shared. We can t share the electrons equally in the bonds, so we put two electrons in one bond, four in another. But, the two bonds are identical, so we have two structures like: The arrow means that the two structures are resonance structures

2 130 Exceptions to the Octet Rule Electron deficient compounds: BF 3 The boron only has a sextet of electrons around it. Octet expansion: I 3 - Atoms that have accessible d-electrons can expand their octets. The central iodine in I 3 - has ten electrons around it. Odd-electron compounds: NO N has 5 valence electrons, O has six. So, 11 electrons are available, five available for sharing. Four go into the double bond, the remaining electron is unpaired on the nitrogen atom. Note that for NO 2, there are two resonance structures. The odd electron is on the nitrogen, and there is no lone pair on N.

3 131 Electron Pair Repulsions and Molecular Structure By considering how many electron pairs surround the central atom in a compound, we can predict the geometry by considering how to minimize the repulsions among all electron pairs. First, we determine the number of electron pairs around the central atom. The electron pairs will arranger themselves to minimize repulsions. We distinguish between bonding electron pairs and lone (nonbonding) pairs. Three kinds of electron pair interactions occur: Bonding pair binding pair Lone pair lone pair Lone pair-bonding pair The prediction of molecular geometries based on these electron pair interactions is called the Valence Shell Electron Pair Repulsion (VSEPR) model. Sometimes also called the Gillispie-Nyholm model This diagram summarizes the geometries arising from various numbers of electron pairs. Sometimes called steric number

4 132 Examples We begin by counting electron pairs around the central atom in a molecule. Let s consider single bonds only. First, draw the Lewis structure. For counting purposes, multiple electron pairs in a multiple bond count as a single pair. The electron pairs will arrange themselves in a way that minimizes repulsion. Example 1: BeCl 2 electron. Be has a (2s) 2 configuration. Each Cl atom provides one bonding With two pairs of electrons, the structure is linear. Example 2: BF 3 As noted above, there are three electron pairs. The electrons arrange themselves around the equator of the sphere. The trigonal planar structure results. Example 3: This is one of the most common examples. H 2 O, NH 3, CH 4 are examples With four electron pairs, the charges arrange themselves at the apexes of a tetrahedron. For H 2 O, two hydrogen occupy two positions at the tetrahedron, two lone pairs also occupy two positions.

5 133 For NH 3, one lone pair occupies a position on the tetrahedron: The lone pairs provide distortions from perfect tetrahedral symmetry The single lone pair provides a distortion of about 2.5, while two lone pairs provide a distortion of about 5 Example 4: Five electron pairs. PCl 5 P has an s 2 p 3 configuration, so 5 electrons from each of five Cl atoms yields 10 electrons. Trigonal bipyramid give minimum energy structure. Now let s consider I = 10 electrons Of the structures given, we must now minimize the lone pair interactions. These are the most repulsive. The last structure (linear) is the most stable.

6 134 Finally, XeF 4 is a case for six electron pairs. Xe contributes 4 pairs. The four F atoms contribute four more electrons. The base structure is the octahedron. Having lone pairs at 180 produces the lowest energy structure. Multiple Bonds When we work out VSEPR structures for systems with multiple bonds, we only count a single electron pair for assigning the appropriate geometry. Consider CO 2 : For a VSEPR analysis, we have only two electron pairs on carbon, and the structure is linear. For O 3, ignoring the multiple bonds, note that there are three electron pairs involved in the bonding. So the molecule is bent.

Vocabulary: VSEPR. 3 domains on central atom. 2 domains on central atom. 3 domains on central atom NOTE: Valence Shell Electron Pair Repulsion Theory

Vocabulary: VSEPR. 3 domains on central atom. 2 domains on central atom. 3 domains on central atom NOTE: Valence Shell Electron Pair Repulsion Theory Vocabulary: VSEPR Valence Shell Electron Pair Repulsion Theory domain = any electron pair, or any double or triple bond is considered one domain. lone pair = non-bonding pair = unshared pair = any electron

More information

Illustrating Bonds - Lewis Dot Structures

Illustrating Bonds - Lewis Dot Structures Illustrating Bonds - Lewis Dot Structures Lewis Dot structures are also known as electron dot diagrams These diagrams illustrate valence electrons and subsequent bonding A line shows each shared electron

More information

EXPERIMENT - 1. Molecular Geometry- Lewis Dot structures

EXPERIMENT - 1. Molecular Geometry- Lewis Dot structures EXPERIMENT - 1 Molecular Geometry- Lewis Dot structures INTRODUCTION Although it has recently become possible to image molecules and even atoms using a high-resolution microscope, most of our information

More information

EXPERIMENT 9 Dot Structures and Geometries of Molecules

EXPERIMENT 9 Dot Structures and Geometries of Molecules EXPERIMENT 9 Dot Structures and Geometries of Molecules INTRODUCTION Lewis dot structures are our first tier in drawing molecules and representing bonds between the atoms. The method was first published

More information

Chemistry 4th Edition McMurry/Fay

Chemistry 4th Edition McMurry/Fay 7 Chapter Covalent Bonding Chemistry 4th Edition McMurry/Fay Dr. Paul Charlesworth Michigan Technological University The Covalent Bond 01 Covalent bonds are formed by sharing at least one pair of electrons.

More information

Effect of unshared pairs on molecular geometry

Effect of unshared pairs on molecular geometry Chapter 7 covalent bonding Introduction Lewis dot structures are misleading, for example, could easily represent that the electrons are in a fixed position between the 2 nuclei. The more correct designation

More information

Lab Manual Supplement

Lab Manual Supplement Objectives 1. Learn about the structures of covalent compounds and polyatomic ions. 2. Draw Lewis structures based on valence electrons and the octet rule. 3. Construct 3-dimensional models of molecules

More information

Chemical Bonding and Molecular Structure (Chapter 10)

Chemical Bonding and Molecular Structure (Chapter 10) Chemical Bonding and Molecular Structure (Chapter 10) Molecular Structure 1. General Summary -- Structure and Bonding Concepts Electronic Configuration of Atoms Octet Rule Lewis Electron Dot ormula of

More information

Lewis Structure Exercise

Lewis Structure Exercise Lewis Structure Exercise A Lewis structure shows how the valence electrons are arranged and indicates the bonding between atoms in a molecule. We represent the elements by their symbols. The shared electron

More information

Lewis Structures. Molecular Shape. VSEPR Model (Valence Shell Electron Pair Repulsion Theory)

Lewis Structures. Molecular Shape. VSEPR Model (Valence Shell Electron Pair Repulsion Theory) Lewis Structures Molecular Shape VSEPR Model (Valence Shell Electron Pair Repulsion Theory) PART 1: Ionic Compounds Complete the table of Part 1 by writing: The Lewis dot structures for each metallic and

More information

Chapter 11. Chemical Bonds: The Formation of Compounds from Atoms

Chapter 11. Chemical Bonds: The Formation of Compounds from Atoms Chapter 11 Chemical Bonds: The Formation of Compounds from Atoms 1 11.1 Periodic Trends in atomic properties 11.1 Periodic Trends in atomic properties design of periodic table is based on observing properties

More information

CH101/105, GENERAL CHEMISTRY LABORATORY

CH101/105, GENERAL CHEMISTRY LABORATORY CH101/105, GENERAL CHEMITRY LABORATORY LABORATORY LECTURE 5 EXPERIMENT 5: LEWI TRUCTURE AND MOLECULAR HAPE Lecture topics I. LEWI TRUCTURE a) calculation of the valence electron numbers; b) choosing the

More information

EXPERIMENT 17 : Lewis Dot Structure / VSEPR Theory

EXPERIMENT 17 : Lewis Dot Structure / VSEPR Theory EXPERIMENT 17 : Lewis Dot Structure / VSEPR Theory Materials: Molecular Model Kit INTRODUCTION Although it has recently become possible to image molecules and even atoms using a high-resolution microscope,

More information

Chapter 5. The covalent bond model

Chapter 5. The covalent bond model Chapter 5 The covalent bond model What s a comin up? Covalent bond model Lewis structures for molecular compounds Multiple bonds Coordinate covalent bonds Guidelines for drawing correct Lewis structures

More information

PREDICTING MOLECULAR SHAPE AND POLARITY USING VSEPR THEORY

PREDICTING MOLECULAR SHAPE AND POLARITY USING VSEPR THEORY EXPERIMENT 2 PREDICTING MOLECULAR SHAPE AND POLARITY USING VSEPR THEORY Materials Needed Molecular model kit. Textbook Reading Smith, chapter 3.10-3.12 Background In this lab, you will practice your understanding

More information

Theme 3: Bonding and Molecular Structure. (Chapter 8)

Theme 3: Bonding and Molecular Structure. (Chapter 8) Theme 3: Bonding and Molecular Structure. (Chapter 8) End of Chapter questions: 5, 7, 9, 12, 15, 18, 23, 27, 28, 32, 33, 39, 43, 46, 67, 77 Chemical reaction valence electrons of atoms rearranged (lost,

More information

ch9 and 10 practice test

ch9 and 10 practice test 1. Which of the following covalent bonds is the most polar (highest percent ionic character)? A. Al I B. Si I C. Al Cl D. Si Cl E. Si P 2. What is the hybridization of the central atom in ClO 3? A. sp

More information

EXPERIMENT 14: COMPARISONS OF THE SHAPES OF MOLECULES AND IONS USING MODELS

EXPERIMENT 14: COMPARISONS OF THE SHAPES OF MOLECULES AND IONS USING MODELS EXPERIMENT 14: CMPARISNS F TE SAPES F MLECULES AND INS USING MDELS PURPSE Models of various molecules and ions will be constructed and their shapes and geometries will be compared. BACKGRUND LEWIS STRUCTURES

More information

Chemical Bonding: Covalent Systems Written by Rebecca Sunderman, Ph.D Week 1, Winter 2012, Matter & Motion

Chemical Bonding: Covalent Systems Written by Rebecca Sunderman, Ph.D Week 1, Winter 2012, Matter & Motion Chemical Bonding: Covalent Systems Written by Rebecca Sunderman, Ph.D Week 1, Winter 2012, Matter & Motion A covalent bond is a bond formed due to a sharing of electrons. Lewis structures provide a description

More information

Unit 28 Molecular Geometry

Unit 28 Molecular Geometry Unit 28 Molecular Geometry There are two concepts in the study of molecular geometry. One is called the Valence Shell Electron Pair Repulsion (VSEPR) model. The other is electron orbital hybridization.

More information

Chapter 8: Bonding General Concepts. Valence Electrons. Representative Elements & Lewis Dot Structures

Chapter 8: Bonding General Concepts. Valence Electrons. Representative Elements & Lewis Dot Structures Chapter 8: Bonding General Concepts Valence Electrons 8.1 Chemical Bond Formation 8.2 Covalent Bonding (Lewis Dot Structures) 8.3 Charge Distribution in Covalent Compounds 8.4 Resonance 8.5 Molecular Shapes

More information

Molecular Models: Lewis Structure and VSEPR Theory

Molecular Models: Lewis Structure and VSEPR Theory Minneapolis Community & Technical College Chemistry Department Chem 1020 Laboratory Molecular Models: Lewis Structure and VSEPR Theory bjectives To determine the Lewis structure for a molecule To determine

More information

Chemical Bonds. a. Duet Rule: 2 electrons needed to satisfy valence shell. i. What follows this rule? Hydrogen and Helium

Chemical Bonds. a. Duet Rule: 2 electrons needed to satisfy valence shell. i. What follows this rule? Hydrogen and Helium Chemical Bonds 1. Important points about Lewis Dot: a. Duet Rule: 2 electrons needed to satisfy valence shell. i. What follows this rule? Hydrogen and Helium b. Octet Rule: 8 electrons needed to satisfy

More information

VSEPR Model. The Valence-Shell Electron Pair Repulsion Model. Predicting Molecular Geometry

VSEPR Model. The Valence-Shell Electron Pair Repulsion Model. Predicting Molecular Geometry VSEPR Model The structure around a given atom is determined principally by minimizing electron pair repulsions. The Valence-Shell Electron Pair Repulsion Model The valence-shell electron pair repulsion

More information

Molecular Geometry and Chemical Bonding Theory

Molecular Geometry and Chemical Bonding Theory Chapter 10 Molecular Geometry and Chemical Bonding Theory Concept Check 10.1 An atom in a molecule is surrounded by four pairs of electrons, one lone pair and three bonding pairs. Describe how the four

More information

Chemistry 3012 Foundational Chemistry Laboratory Manual

Chemistry 3012 Foundational Chemistry Laboratory Manual Chemistry 3012 Foundational Chemistry Laboratory Manual Table of Contents Page Experiment 1. Experiment 2. Experiment 3. Experiment 4. Experiment 5. Experiment 6. Experiment 7. Experiment 8. Determining

More information

Health Science Chemistry I CHEM-1180 Experiment No. 15 Molecular Models (Revised 05/22/2015)

Health Science Chemistry I CHEM-1180 Experiment No. 15 Molecular Models (Revised 05/22/2015) (Revised 05/22/2015) Introduction In the early 1900s, the chemist G. N. Lewis proposed that bonds between atoms consist of two electrons apiece and that most atoms are able to accommodate eight electrons

More information

5. Which of the following is the correct Lewis structure for SOCl 2

5. Which of the following is the correct Lewis structure for SOCl 2 Unit C Practice Problems Chapter 8 1. Draw the lewis structures for the following molecules: a. BeF 2 b. SO 3 c. CNS 1- d. NO 2. The correct Lewis symbol for ground state carbon is a) b) c) d) e) 3. Which

More information

Lewis Structures & the VSEPR Model

Lewis Structures & the VSEPR Model Lewis Structures & the VSEPR Model A Directed Learning Activity for Hartnell College Chemistry 1 Funded by the Title V STEM Grant #P031S090007 through Hartnell College For information contact lyee@hartnell.edu

More information

Laboratory 11: Molecular Compounds and Lewis Structures

Laboratory 11: Molecular Compounds and Lewis Structures Introduction Laboratory 11: Molecular Compounds and Lewis Structures Molecular compounds are formed by sharing electrons between non-metal atoms. A useful theory for understanding the formation of molecular

More information

Chapter 9 Molecular Geometry and Bonding Theories

Chapter 9 Molecular Geometry and Bonding Theories Chapter 9 Molecular Geometry and Bonding Theories 1. or a molecule with the formula AB 2 the molecular shape is. (a). linear or trigonal planar (b). linear or bent (c). linear or T-shaped (d). T-shaped

More information

Covalent Bonding and Molecular Geometry

Covalent Bonding and Molecular Geometry Name Section # Date of Experiment Covalent Bonding and Molecular Geometry When atoms combine to form molecules (this also includes complex ions) by forming covalent bonds, the relative positions of the

More information

2. Atoms with very similar electronegativity values are expected to form

2. Atoms with very similar electronegativity values are expected to form AP hemistry Practice Test #6 hapter 8 and 9 1. Which of the following statements is incorrect? a. Ionic bonding results from the transfer of electrons from one atom to another. b. Dipole moments result

More information

THE STRUCTURE OF MOLECULES AN EXPERIMENT USING MOLECULAR MODELS 2009 by David A. Katz. All rights reserved.

THE STRUCTURE OF MOLECULES AN EXPERIMENT USING MOLECULAR MODELS 2009 by David A. Katz. All rights reserved. THE STRUCTURE OF MOLECULES AN EXPERIMENT USING MOLECULAR MODELS 2009 by David A. Katz. All rights reserved. In a footnot to a 1857 paper, Friedrich August Kekulé suggested that carbon was tetratomic, that

More information

Laboratory 20: Review of Lewis Dot Structures

Laboratory 20: Review of Lewis Dot Structures Introduction The purpose of the laboratory exercise is to review Lewis dot structures and expand on topics discussed in class. Additional topics covered are the general shapes and bond angles of different

More information

Chapter 12 Review 1: Covalent Bonds and Molecular Structure

Chapter 12 Review 1: Covalent Bonds and Molecular Structure Chapter 12 Review 1: Covalent Bonds and Molecular Structure 1) How are ionic bonds and covalent bonds different, and what types of elements combine to form each? Ionic bonds result from the transfer of

More information

What Are the Shapes of Molecules?

What Are the Shapes of Molecules? Lab 7 Name What Are the Shapes of Molecules? Pre-Lab Assignment Read the entire lab handout. There is no written pre-lab assignment for this lab. Learning Goals Derive the Lewis structure of a covalent

More information

Name: Class: Date: 3) The bond angles marked a, b, and c in the molecule below are about,, and, respectively.

Name: Class: Date: 3) The bond angles marked a, b, and c in the molecule below are about,, and, respectively. Name: Class: Date: Unit 9 Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The basis of the VSEPR model of molecular bonding is. A) regions of

More information

Valence shell electrons repel each other Valence shell electrons are arranged geometrically around the central atom to

Valence shell electrons repel each other Valence shell electrons are arranged geometrically around the central atom to Molecular Geometry (Valence Shell Electron Pair Repulsion -VSEPR) & Hybridization of Atomic Orbitals (Valance Bond Theory) Chapter 10 Valence Shell Electron Pair Repulsion (VSEPR) Valence shell electrons

More information

CHEM 110 Exam 2 - Practice Test 1 - Solutions

CHEM 110 Exam 2 - Practice Test 1 - Solutions CHEM 110 Exam 2 - Practice Test 1 - Solutions 1D 1 has a triple bond. 2 has a double bond. 3 and 4 have single bonds. The stronger the bond, the shorter the length. 2A A 1:1 ratio means there must be the

More information

Lewis Dot Structure Answer Key

Lewis Dot Structure Answer Key Lewis Dot Structure Answer Key 1) Nitrogen is the central atom in each of the following species: N2 N2 - N2 + Nitrogen can also form electron deficient compounds with a single unpaired electron on the

More information

Valence Bond Theory - Description

Valence Bond Theory - Description Bonding and Molecular Structure - PART 2 - Valence Bond Theory and Hybridization 1. Understand and be able to describe the Valence Bond Theory description of covalent bond formation. 2. Understand and

More information

George Mason University General Chemistry 211 Chapter 10 The Shapes (Geometry) of Molecules

George Mason University General Chemistry 211 Chapter 10 The Shapes (Geometry) of Molecules Acknowledgements George Mason University General Chemistry 211 Chapter 10 The Shapes (Geometry) of Molecules Course Text Chemistry the Molecular Nature of Matter and Change, 7 th edition, 2011, McGraw-Hill

More information

AP Chemistry A. Allan Chapter 8 Notes - Bonding: General Concepts

AP Chemistry A. Allan Chapter 8 Notes - Bonding: General Concepts AP Chemistry A. Allan Chapter 8 Notes - Bonding: General Concepts 8.1 Types of Chemical Bonds A. Ionic Bonding 1. Electrons are transferred 2. Metals react with nonmetals 3. Ions paired have lower energy

More information

The Lewis electron dot structures below indicate the valence electrons for elements in Groups 1-2 and Groups 13-18

The Lewis electron dot structures below indicate the valence electrons for elements in Groups 1-2 and Groups 13-18 AP EMISTRY APTER REVIEW APTER 7: VALENT BNDING You should understand the nature of the covalent bond. You should be able to draw the Lewis electron-dot structure for any atom, molecule, or polyatomic ion.

More information

7.14 Linear triatomic: A-----B-----C. Bond angles = 180 degrees. Trigonal planar: Bond angles = 120 degrees. B < B A B = 120

7.14 Linear triatomic: A-----B-----C. Bond angles = 180 degrees. Trigonal planar: Bond angles = 120 degrees. B < B A B = 120 APTER SEVEN Molecular Geometry 7.13 Molecular geometry may be defined as the three-dimensional arrangement of atoms in a molecule. The study of molecular geometry is important in that a molecule s geometry

More information

Structures and Properties of Substances. Introducing Valence-Shell Electron- Pair Repulsion (VSEPR) Theory

Structures and Properties of Substances. Introducing Valence-Shell Electron- Pair Repulsion (VSEPR) Theory Structures and Properties of Substances Introducing Valence-Shell Electron- Pair Repulsion (VSEPR) Theory The VSEPR theory In 1957, the chemist Ronald Gillespie and Ronald Nyholm, developed a model for

More information

Molecular Geometry and VSEPR We gratefully acknowledge Portland Community College for the use of this experiment.

Molecular Geometry and VSEPR We gratefully acknowledge Portland Community College for the use of this experiment. Molecular and VSEPR We gratefully acknowledge Portland ommunity ollege for the use of this experiment. Objectives To construct molecular models for covalently bonded atoms in molecules and polyatomic ions

More information

ACE PRACTICE TEST Chapter 8, Quiz 3

ACE PRACTICE TEST Chapter 8, Quiz 3 ACE PRACTICE TEST Chapter 8, Quiz 3 1. Using bond energies, calculate the heat in kj for the following reaction: CH 4 + 4 F 2 CF 4 + 4 HF. Use the following bond energies: CH = 414 kj/mol, F 2 = 155 kj/mol,

More information

5. Which of the following subatomic particles are most important in determining the chemical reactivity and physical properties of an atom?

5. Which of the following subatomic particles are most important in determining the chemical reactivity and physical properties of an atom? 1. For the following compounds draw the Lewis Structure and determine: (a) The # of Bonding Pairs (b) The # of Lone pairs (c) The electron domain shape (d) The molecular shape (e) Hybridization (f) Whether

More information

11 Chemical Bonds: The Formation of Compounds from Atoms. Chapter Outline. Periodic Trends in Atomic Properties. Periodic Trends in Atomic Properties

11 Chemical Bonds: The Formation of Compounds from Atoms. Chapter Outline. Periodic Trends in Atomic Properties. Periodic Trends in Atomic Properties 11 Chemical Bonds The Formation of Compounds from Atoms Chapter Outline 11.1 11.2 Lewis Structures of Atoms 11.3 The Ionic Bond Transfer of Electrons from One Atom to Another 11.4 Predicting Formulas of

More information

COVALENT BONDING. [MH5; Chapter 7]

COVALENT BONDING. [MH5; Chapter 7] COVALENT BONDING [MH5; Chapter 7] Covalent bonds occur when electrons are equally shared between two atoms. The electrons are not always equally shared by both atoms; these bonds are said to be polar covalent.

More information

Both molecules have the same polarity. Circle the word that describes the polarity of these molecules. polar non-polar Justify your choice.

Both molecules have the same polarity. Circle the word that describes the polarity of these molecules. polar non-polar Justify your choice. QUESTION (2015:1) (c) BeCl2 and BF3 are unusual molecules because there are not enough electrons for the central atoms, Be and B, to have a full valence shell. Their Lewis structures are shown below. Both

More information

Chapter 9-10 practice test

Chapter 9-10 practice test Class: Date: Chapter 9-10 practice test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which one of the following is most likely to be an ionic compound?

More information

Drawing Lewis Structures

Drawing Lewis Structures Drawing Lewis Structures 1. Add up all of the valence electrons for the atoms involved in bonding 2. Write the symbols for the elements and show connectivity with single bonds (2 electrons shared). a.

More information

EXAM 4 CH (Blackstock) November 30, 2006

EXAM 4 CH (Blackstock) November 30, 2006 EXAM 4 CH101.004 (Blackstock) November 30, 2006 Student name (print): honor pledge: 1. Which of these choices is the general electron configuration for the outermost electrons of elements in the alkaline

More information

Hybrid Atomic Orbitals

Hybrid Atomic Orbitals Hybrid Atomic Orbitals These materials were adapted from Prof. George Bodner, Purdue University (http:// chemed.chem.purdue.edu/genchem/topicreview/bp/ch8/hybrid.html#geom; excerpted 08/25/2011). This

More information

Chemistry Workbook 2: Problems For Exam 2

Chemistry Workbook 2: Problems For Exam 2 Chem 1A Dr. White Updated /5/1 1 Chemistry Workbook 2: Problems For Exam 2 Section 2-1: Covalent Bonding 1. On a potential energy diagram, the most stable state has the highest/lowest potential energy.

More information

Molecular Structures

Molecular Structures E x p e r i m e n t Molecular Structures Objectives To determine the number of valence electrons in molecules. To determine the Lewis structure of molecules. To determine the electron pair geometry and

More information

3.4 Covalent Bonds and Lewis Structures

3.4 Covalent Bonds and Lewis Structures 3.4 Covalent Bonds and Lewis Structures The Lewis Model of Chemical Bonding In 1916 G. N. Lewis proposed that atoms combine in order to achieve a more stable electron configuration. Maximum stability results

More information

Ch 8-9 Practice Test Answer Key

Ch 8-9 Practice Test Answer Key Ch 8-9 Practice Test Answer Key 18. Which of the atoms below is least likely to violate the octet rule? a) Be- deficient likely b) P- can expland c) S- can expand d) B- deficient is likely e) F- usually

More information

Covalent Bonds: overlap of orbitals σ-bond π-bond Molecular Orbitals

Covalent Bonds: overlap of orbitals σ-bond π-bond Molecular Orbitals Covalent Bonding What is covalent bonding? Covalent Bonds: overlap of orbitals σ-bond π-bond Molecular Orbitals Hybrid Orbital Formation Shapes of Hybrid Orbitals Hybrid orbitals and Multiple Bonds resonance

More information

CHAPTER NOTES CHAPTER 16. Covalent Bonding

CHAPTER NOTES CHAPTER 16. Covalent Bonding CHAPTER NOTES CHAPTER 16 Covalent Bonding Goals : To gain an understanding of : NOTES: 1. Valence electron and electron dot notation. 2. Stable electron configurations. 3. Covalent bonding. 4. Polarity

More information

A pure covalent bond is an equal sharing of shared electron pair(s) in a bond. A polar covalent bond is an unequal sharing.

A pure covalent bond is an equal sharing of shared electron pair(s) in a bond. A polar covalent bond is an unequal sharing. CHAPTER EIGHT BNDING: GENERAL CNCEPT or Review 1. Electronegativity is the ability of an atom in a molecule to attract electrons to itself. Electronegativity is a bonding term. Electron affinity is the

More information

CHAPTER 10 THE SHAPES OF MOLECULES

CHAPTER 10 THE SHAPES OF MOLECULES ATER 10 TE AE MLEULE EMIAL ETI BED READIG RBLEM B10.1 lan: Examine the Lewis structure, noting the number of regions of electron density around the carbon and nitrogen atoms in the two resonance structures.

More information

Self Assessment_Ochem I

Self Assessment_Ochem I UTID: 2013 Objective Test Section Identify the choice that best completes the statement or answers the question. There is only one correct answer; please carefully bubble your choice on the scantron sheet.

More information

Chapter 10: Chemical Bonding II: Molecular Shapes; VSEPR, Valence Bond and Molecular Orbital Theories

Chapter 10: Chemical Bonding II: Molecular Shapes; VSEPR, Valence Bond and Molecular Orbital Theories C h e m i s t r y 1 A : C h a p t e r 1 0 P a g e 1 Chapter 10: Chemical Bonding II: Molecular Shapes; VSEPR, Valence Bond and Molecular Orbital Theories Homework: Read Chapter 10: Work out sample/practice

More information

Unit 8: Drawing Molecules

Unit 8: Drawing Molecules Unit 8: Drawing Molecules bjectives Topic 1: Lewis Dot Diagrams & Ionic Bonding 1. Draw a Lewis dot diagram of any representative element. 2. Draw a Lewis dot diagram of any ionic compound. A Lewis structure

More information

Geometries and Valence Bond Theory Worksheet

Geometries and Valence Bond Theory Worksheet Geometries and Valence Bond Theory Worksheet Also do Chapter 10 textbook problems: 33, 35, 47, 49, 51, 55, 57, 61, 63, 67, 83, 87. 1. Fill in the tables below for each of the species shown. a) CCl 2 2

More information

Lewis Dot Structures. A How To

Lewis Dot Structures. A How To Lewis Dot Structures A How To Step 1 Count the total valence electrons for the molecule To do this, find the number of valence electrons for each atom in the molecule, and add them up. CO 2 Step 1: Valance

More information

Background: Electron Dot Formula Basics

Background: Electron Dot Formula Basics Background: Electron Dot Formula Basics 1. What do the dots in an electron dot formula represent? 2. Describe the pattern of electron dot formulas as you move from left to right in a period of the Periodic

More information

Shapes of Molecules and Bonding

Shapes of Molecules and Bonding Shapes of Molecules and onding Molecular geometry is governed by energy. Molecules receive such geometry as to minimize their potential energy. A striking example is DA. Lewis Dot Structures 1. VAL (total

More information

Chapter 7. Comparing Ionic and Covalent Bonds. Ionic Bonds. Types of Bonds. Quick Review of Bond Types. Covalent Bonds

Chapter 7. Comparing Ionic and Covalent Bonds. Ionic Bonds. Types of Bonds. Quick Review of Bond Types. Covalent Bonds Comparing Ionic and Covalent Bonds Chapter 7 Covalent Bonds and Molecular Structure Intermolecular forces (much weaker than bonds) must be broken Ionic bonds must be broken 1 Ionic Bonds Covalent Bonds

More information

Chapter 8. Chemical Bonding. Introduction. Molecular and Ionic Compounds. Chapter 8 Topics. Ionic and Covalent. Ionic and Covalent

Chapter 8. Chemical Bonding. Introduction. Molecular and Ionic Compounds. Chapter 8 Topics. Ionic and Covalent. Ionic and Covalent Introduction Chapter 8 Chemical Bonding How and why to atoms come together (bond) to form compounds? Why do different compounds have such different properties? What do molecules look like in 3 dimensions?

More information

Bonding Models. Bonding Models (Lewis) Bonding Models (Lewis) Resonance Structures. Section 2 (Chapter 3, M&T) Chemical Bonding

Bonding Models. Bonding Models (Lewis) Bonding Models (Lewis) Resonance Structures. Section 2 (Chapter 3, M&T) Chemical Bonding Bonding Models Section (Chapter, M&T) Chemical Bonding We will look at three models of bonding: Lewis model Valence Bond model M theory Bonding Models (Lewis) Bonding Models (Lewis) Lewis model of bonding

More information

Assignment 9 Solutions. Chapter 8, #8.32, 36, 38, 42, 54, 56, 72, 100, 102, Chapter 10, #10.24, 40, 55, 63. Number of e in Valence Shell

Assignment 9 Solutions. Chapter 8, #8.32, 36, 38, 42, 54, 56, 72, 100, 102, Chapter 10, #10.24, 40, 55, 63. Number of e in Valence Shell Assignment 9 Solutions Chapter 8, #8.32, 36, 38, 42, 54, 56, 72, 100, 102, Chapter 10, #10.24, 40, 55, 63. 8.32. Collect and Organize Of B 3+, I, Ca 2+, and Pb 2+ we are to identify which have a complete

More information

CHEMISTRY BONDING REVIEW

CHEMISTRY BONDING REVIEW Answer the following questions. CHEMISTRY BONDING REVIEW 1. What are the three kinds of bonds which can form between atoms? The three types of Bonds are Covalent, Ionic and Metallic. Name Date Block 2.

More information

Question 4.2: Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.

Question 4.2: Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br. Question 4.1: Explain the formation of a chemical bond. A chemical bond is defined as an attractive force that holds the constituents (atoms, ions etc.) together in a chemical species. Various theories

More information

Note that each line between atoms represents a bond, which contains 2 electrons.

Note that each line between atoms represents a bond, which contains 2 electrons. Octet Rule and Lewis Dot Structures CH2000: Introduction to General Chemistry, Plymouth State University Introduction: In the late 1800s, chemists were working to make sense of the large numbers of compounds

More information

Covalent Bonds. A group of atoms held together by covalent bonds is called a molecule.

Covalent Bonds. A group of atoms held together by covalent bonds is called a molecule. Covalent Bonds The bond formed when atoms share electrons is called a covalent bond. (Unlike ionic bonds, which involve the complete transfer of electrons). A group of atoms held together by covalent bonds

More information

CHAPTER 10 THE SHAPES OF MOLECULES

CHAPTER 10 THE SHAPES OF MOLECULES ATER 10 TE AE MLEULE 10.1 To be the central atom in a compound, the atom must be able to simultaneously bond to at least two other atoms. e,, and cannot serve as central atoms in a Lewis structure. elium

More information

3. Simple Bonding Theory Lewis Electron-Dot Diagrams & Resonance. 3.1 Lewis-Representation of simple molecules such as ??

3. Simple Bonding Theory Lewis Electron-Dot Diagrams & Resonance. 3.1 Lewis-Representation of simple molecules such as ?? 3. Simple Bonding Theory 3. 1 Lewis Electron-Dot Diagrams & Resonance 3.1 Lewis-Representation of simple molecules such as F 2, N 2, H 2 O, H-C C-H, or CO 2 (but how about O 2??) 3.1.1 Resonance Structures

More information

Chapter10 Tro. 4. Based on the Lewis structure, the number of electron domains in the valence shell of the CO molecule is A) 1 B) 2 C) 3 D) 4 E) 5

Chapter10 Tro. 4. Based on the Lewis structure, the number of electron domains in the valence shell of the CO molecule is A) 1 B) 2 C) 3 D) 4 E) 5 Chapter10 Tro 1. All of the geometries listed below are examples of the five basic geometries for molecules with more than 3 atoms except A) planar triangular B) octahedral C) tetrahedral D) trihedral

More information

Molecular Geometry. How can molecular shapes be predicted using the VSEPR theory? H 2. CO 3 electron domains (3 bonding, 0 nonbonding)

Molecular Geometry. How can molecular shapes be predicted using the VSEPR theory? H 2. CO 3 electron domains (3 bonding, 0 nonbonding) Why? Molecular Geometry How can molecular shapes be predicted using the VSEPR theory? When you draw a Lewis structure for a molecule on paper, you are making a two-dimensional representation of the atoms.

More information

UNIT TEST Atomic & Molecular Structure. Name: Date:

UNIT TEST Atomic & Molecular Structure. Name: Date: SCH4U UNIT TEST Atomic & Molecular Structure Name: _ Date: Part A - Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Who postulated that electrons

More information

Bonding & Molecular Shape Ron Robertson

Bonding & Molecular Shape Ron Robertson Bonding & Molecular Shape Ron Robertson r2 n:\files\courses\1110-20\2010 possible slides for web\00bondingtrans.doc The Nature of Bonding Types 1. Ionic 2. Covalent 3. Metallic 4. Coordinate covalent Driving

More information

Topic 4. Chemical bonding and structure

Topic 4. Chemical bonding and structure Topic 4. Chemical bonding and structure There are three types of strong bonds: Ionic Covalent Metallic Some substances contain both covalent and ionic bonding or an intermediate. 4.1 Ionic bonding Ionic

More information

5. Structure, Geometry, and Polarity of Molecules

5. Structure, Geometry, and Polarity of Molecules 5. Structure, Geometry, and Polarity of Molecules What you will accomplish in this experiment This experiment will give you an opportunity to draw Lewis structures of covalent compounds, then use those

More information

Experiment 5 Can You Model This?

Experiment 5 Can You Model This? Experiment 5 Can You Model This? OUTCOMES After completing this experiment, the student should be able to: Differentiate between molecular compounds and ionic compounds. Construct Lewis-dot structures

More information

Chemical Bonds, Molecular Models and Shapes

Chemical Bonds, Molecular Models and Shapes Chem 100 Section Experiment 6 Chemical Bonds, Molecular Models and Shapes Introduction The properties of chemical compounds are directly related to the ways in which atoms are bonded together into molecules.

More information

8/19/2011. Periodic Trends and Lewis Dot Structures. Review PERIODIC Table

8/19/2011. Periodic Trends and Lewis Dot Structures. Review PERIODIC Table Periodic Trends and Lewis Dot Structures Chapter 11 Review PERIODIC Table Recall, Mendeleev and Meyer organized the ordering the periodic table based on a combination of three components: 1. Atomic Number

More information

Lecture 24: Lewis Dot Structures

Lecture 24: Lewis Dot Structures Lecture 24: Lewis Dot Structures Reading: Zumdahl 13.9-13.12 utline Lewis Dot Structures (LDS) Localized Electron (LE) Bonding Picture Resonance Those annoying exceptions Problems (Chapter 13, Zumdahl

More information

Valence Electrons. core and CHAPTER 9. Introduction. Bonds - Attractive forces that hold atoms together in compounds

Valence Electrons. core and CHAPTER 9. Introduction. Bonds - Attractive forces that hold atoms together in compounds Structure and Molecular Bonding CAPTER 9 1 Introduction Bonds - Attractive forces that hold atoms together in compounds Valence Electrons - The electrons involved in bonding are in the outermost (valence)

More information

SHAPES OF MOLECULES (VSEPR MODEL)

SHAPES OF MOLECULES (VSEPR MODEL) 1 SAPES MLEULES (VSEPR MDEL) Valence Shell Electron-Pair Repulsion model - Electron pairs surrounding atom spread out as to minimize repulsion. - Electron pairs can be bonding pairs (including multiple

More information

CH 222 Chapter Seven Concept Guide

CH 222 Chapter Seven Concept Guide CH 222 Chapter Seven Concept Guide 1. Lewis Structures Draw the Lewis Dot Structure for cyanide ion, CN -. 1 C at 4 electrons = 4 electrons 1 N at 5 electrons = 5 electrons -1 charge = + 1 electron Total

More information

Linear (2 atoms around central atom) Trigonal Planar (3 atoms around central atom) Tetrahedral (pyramid has 4 faces) (4 atoms around central atom)

Linear (2 atoms around central atom) Trigonal Planar (3 atoms around central atom) Tetrahedral (pyramid has 4 faces) (4 atoms around central atom) Step by step: Drawing Molecular Structures / Lewis Structures Molecular Shapes and Names **The names refer to where the atoms are located, not where the electrons are located!** Linear Linear (2 atoms

More information

Look at the shape of many molecules, and compare this to the shape of the orbitals of each of the atoms.

Look at the shape of many molecules, and compare this to the shape of the orbitals of each of the atoms. Localized electron model for bonding 190 1. Determine the Lewis Structure for the molecule 2. Determine resonance structures 3. Determine the shape of the molecule 4. Determine the hybridization of the

More information

Recall that ionic bonds form when the combining atoms give up or accept electrons. Another way that atoms can combine is by sharing electrons.

Recall that ionic bonds form when the combining atoms give up or accept electrons. Another way that atoms can combine is by sharing electrons. Molecular Compounds and Covalent Bonds Recall that ionic bonds form when the combining atoms give up or accept electrons. Another way that atoms can combine is by sharing electrons. Atoms that are held

More information

Covalent Bonding & Molecular Compounds Multiple Choice Review PSI Chemistry

Covalent Bonding & Molecular Compounds Multiple Choice Review PSI Chemistry Covalent Bonding & Molecular Compounds Multiple Choice Review PSI Chemistry Name 1) Which pair of elements is most apt to form a molecular compound with each other? A) aluminum, oxygen B) magnesium, iodine

More information

Hybrid Molecular Orbitals

Hybrid Molecular Orbitals Hybrid Molecular Orbitals Last time you learned how to construct molecule orbital diagrams for simple molecules based on the symmetry of the atomic orbitals. Molecular orbitals extend over the entire molecule

More information