3.4 Covalent Bonds and Lewis Structures
|
|
|
- Irene Snow
- 7 years ago
- Views:
Transcription
1 3.4 Covalent Bonds and Lewis Structures
2 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 when an atom is isoelectronic with a noble gas. An electron pair that is shared between two atoms constitutes a covalent bond.
3 Covalent Bonding in 2 Two hydrogen atoms, each with 1 electron,.. can share those electrons in a covalent bond. : Sharing the electron pair gives each hydrogen an electron configuration analogous to helium.
4 Covalent Bonding in F 2 Two fluorine atoms, each with 7 valence electrons, F. :. F: can share those electrons in a covalent bond. : F: F : Sharing the electron pair gives each fluorine an electron configuration analogous to neon.
5 The Octet Rule In forming compounds, atoms gain, lose, or share electrons to give a stable electron configuration characterized by 8 valence electrons. : F: F : The octet rule is the most useful in cases involving covalent bonds to C, N, O, and F.
6 Example Combine carbon (4 valence electrons) and four fluorines (7 valence electrons each).. C.. : F. to write a Lewis structure for CF 4. : F: : F: C : F: : F: The octet rule is satisfied for carbon and each fluorine.
7 Example It is common practice to represent a covalent bond by a line. We can rewrite : F: : F: C : F: : F: as : F: : F C F: : F:
8 3.4 Double Bonds and Triple Bonds
9 Inorganic examples : O: : C :: O: : C Ȯ Ȯ.. : Carbon dioxide : C : :: N : C N: ydrogen cyanide
10 Organic examples : C :: C : Ethylene C C : C : :: C : Acetylene C C
11 3.4 Formal Charges Formal charge is the charge calculated for an atom in a Lewis structure on the basis of an equal sharing of bonded electron pairs.
12 Nitric acid Formal charge of O N O: : O : We will calculate the formal charge for each atom in this Lewis structure.
13 Nitric acid Formal charge of O N O: : O : ydrogen shares 2 electrons with oxygen. Assign 1 electron to and 1 to O. A neutral hydrogen atom has 1 electron. Therefore, the formal charge of in nitric acid is 0.
14 Nitric acid Formal charge of O O N O: : O : Oxygen has 4 electrons in covalent bonds. Assign 2 of these 4 electrons to O. Oxygen has 2 unshared pairs. Assign all 4 of these electrons to O. Therefore, the total number of electrons assigned to O is = 6.
15 Nitric acid Formal charge of O O N O: : O : Electron count of O is 6. A neutral oxygen has 6 electrons. Therefore, the formal charge of O is 0.
16 Nitric acid Formal charge of O O N O: : O : Electron count of O is 6 (4 electrons from unshared pairs + half of 4 bonded electrons). A neutral oxygen has 6 electrons. Therefore, the formal charge of O is 0.
17 Nitric acid Formal charge of O O N O: : O : Electron count of O is 7 (6 electrons from unshared pairs + half of 2 bonded electrons). A neutral oxygen has 6 electrons. Therefore, the formal charge of O is -1.
18 Nitric acid Formal charge of N O O: N : O : Electron count of N is 4 (half of 8 electrons in covalent bonds). A neutral nitrogen has 5 electrons. Therefore, the formal charge of N is +1.
19 Nitric acid Formal charges O O: N+ : O : A Lewis structure is not complete unless formal charges (if any) are shown.
20 Formal Charge An arithmetic formula for calculating formal charge. Formal charge = group number in periodic table number of bonds number of unshared electrons
21 "Electron counts" and formal charges in N + 4 and BF N : F: : F B F: 7 4 : F: 4
22 3.5 Drawing Lewis Structures
23 Constitution The order in which the atoms of a molecule are connected is called its constitution or connectivity. The constitution of a molecule must be determined in order to write a Lewis structure.
24 Table 1.4 ow to Write Lewis Structures Step 1: The molecular formula and the connectivity are determined by experiment.
25 Table 1.4 ow to Write Lewis Structures Step 1: The molecular formula and the connectivity are determined by experiment. Example: Methyl nitrite has the molecular formula C 3 NO 2. All hydrogens are bonded to carbon, and the order of atomic connections is CONO.
26 Table 1.4 ow to Write Lewis Structures Step 2: Count the number of valence electrons. For a neutral molecule this is equal to the number of valence electrons of the constituent atoms.
27 Table 1.4 ow to Write Lewis Structures Step 2: Count the number of valence electrons. For a neutral molecule this is equal to the number of valence electrons of the constituent atoms. Example (C 3 NO 2 ): Each hydrogen contributes 1 valence electron. Each carbon contributes 4, nitrogen 5, and each oxygen 6 for a total of 24.
28 Table 1.4 ow to Write Lewis Structures Step 3: Connect the atoms by a covalent bond represented by a dash.
29 Table 1.4 ow to Write Lewis Structures Step 3: Connect the atoms by a covalent bond represented by a dash. Example: Methyl nitrite has the partial structure: C O N O
30 Table 1.4 ow to Write Lewis Structures Step 4: Subtract the number of electrons in bonds from the total number of valence electrons. C O N O
31 Table 1.4 ow to Write Lewis Structures Step 4: Subtract the number of electrons in bonds from the total number of valence electrons. Example: 24 valence electrons 12 electrons in bonds. Therefore, 12 more electrons to assign.
32 Table 1.4 ow to Write Lewis Structures Step 5: Add electrons in pairs so that as many atoms as possible have 8 electrons. Start with the most electronegative atom.
33 Table 1.4 ow to Write Lewis Structures Step 5: Example: Add electrons in pairs so that as many atoms as possible have 8 electrons. Start with the most electronegative atom. The remaining 12 electrons in methyl nitrite are added as 6 pairs. C O N O :
34 Table 1.4 ow to Write Lewis Structures Step 6: Example: If an atom lacks an octet, use electron pairs on an adjacent atom to form a double or triple bond. Nitrogen has only 6 electrons in the structure shown. C O N O :
35 Table 1.4 ow to Write Lewis Structures Step 6: Example: If an atom lacks an octet, use electron pairs on an adjacent atom to form a double or triple bond. All the atoms have octets in this Lewis structure. C O N O:
36 Table 1.4 ow to Write Lewis Structures Step 7: Calculate formal charges. Example: None of the atoms possess a formal charge in this Lewis structure. C O N O:
37 Table 1.4 ow to Write Lewis Structures Step 7: Calculate formal charges. Example: This structure has formal charges; is less stable Lewis structure. + C O N O :
38 Condensed structural formulas Lewis structures in which many (or all) covalent bonds and electron pairs are omitted. C C C can be condensed to: : O: C 3 CC 3 or (C 3 ) 2 CO O
39 3.5 Constitutional Isomers
40 Constitutional isomers Isomers are different compounds that have the same molecular formula. Constitutional isomers are isomers that differ in the order in which the atoms are connected. An older term for constitutional isomers is structural isomers.
41 A istorical Note N 4 OCN Ammonium cyanate 2 NCN 2 Urea In 1823 Friedrich Wöhler discovered that when ammonium cyanate was dissolved in hot water, it was converted to urea. Ammonium cyanate and urea are constitutional isomers of C 4 N 2 O. Ammonium cyanate is inorganic. Urea is organic. Wöhler is credited with an important early contribution that helped overturn the theory of vitalism. O
42 Examples of constitutional C O: N+ : O : Nitromethane isomers C O N O: Methyl nitrite Both have the molecular formula C 3 NO 2 but the atoms are connected in a different order.
43 3.5 Resonance
44 Resonance two or more acceptable octet Lewis structures may be written for certain compounds (or ions)
45 Table 1.4 ow to Write Lewis Structures Step 6: Example: If an atom lacks an octet, use electron pairs on an adjacent atom to form a double or triple bond. Nitrogen has only 6 electrons in the structure shown. C O N O :
46 Table 1.4 ow to Write Lewis Structures Step 6: If an atom lacks an octet, use electron pairs on an adjacent atom to form a double or triple bond. Example: All the atoms have octets in this Lewis structure. C O N O:
47 Table 1.4 ow to Write Lewis Structures Step 7: Calculate formal charges. Example: None of the atoms possess a formal charge in this Lewis structure. C O N O:
48 Table 1.4 ow to Write Lewis Structures Step 7: Calculate formal charges. Example: This structure has formal charges; is less stable Lewis structure. + C O N O :
49 Resonance Structures of Methyl Nitrite more stable Lewis structure same atomic positions differ in electron positions C O N O: + C O N O : less stable Lewis structure
50 Resonance Structures of Methyl Nitrite C O N O: more stable Lewis structure same atomic positions differ in electron positions + C O N O : less stable Lewis structure
51 Why Write Resonance Structures? Electrons in molecules are often delocalized between two or more atoms. Electrons in a single Lewis structure are assigned to specific atoms-a single Lewis structure is insufficient to show electron delocalization. Composite of resonance forms more accurately depicts electron distribution.
52 Example Ozone (O 3 ) Lewis structure of ozone shows one double bond and one single bond O + O O Expect: one short bond and one long bond Reality: bonds are of equal length (128 pm)
53 Example Ozone (O 3 ) Lewis structure of ozone shows one double bond and one single bond O + O O Resonance: O + O O O O + O
54 3.7 The Shapes of Some Simple Molecules
55
56
57 Methane tetrahedral geometry C angle = 109.5
58 Methane tetrahedral geometry each C angle = 109.5
59 Valence Shell Electron Pair Repulsions The most stable arrangement of groups attached to a central atom is the one that has the maximum separation of electron pairs (bonded or nonbonded).
60 Water bent geometry O angle = 105 O : but notice the tetrahedral arrangement of electron pairs
61 Ammonia trigonal pyramidal geometry N angle = 107 N : but notice the tetrahedral arrangement of electron pairs
62 Boron Trifluoride F B F angle = 120 trigonal planar geometry allows for maximum separation of three electron pairs
63 Multiple Bonds Four-electron double bonds and six-electron triple bonds are considered to be similar to a two-electron single bond in terms of their spatial requirements.
64 Formaldehyde: C 2 =O C and C O angles are close to 120 trigonal planar geometry C O
65 Figure 1.12: Carbon Dioxide O C O angle = 180 linear geometry O C O
66
67
68 3.7: Polar Covalent Bonds and Electronegativity
69 Electronegativity Electronegativity is a measure of an element to attract electrons toward itself when bonded to another element. An electronegative element attracts electrons. An electropositive element releases electrons.
70 Pauling Electronegativity Scale Li Be B C N O F Na Mg Al Si P S Cl Electronegativity increases from left to right in the periodic table. Electronegativity decreases going down a group.
71
72 Generalization The greater the difference in electronegativity between two bonded atoms; the more polar the bond. : F F: :N N: nonpolar bonds connect atoms of the same electronegativity
73 Generalization The greater the difference in electronegativity between two bonded atoms; the more polar the bond. d+ d- F: d+ d- Ȯ. d+ d- d+ d- :O C O: polar bonds connect atoms of different electronegativity
74 3.7 Molecular Dipole Moments
75 Dipole Moment A substance possesses a dipole moment if its centers of positive and negative charge do not coincide. m= e x d (expressed in Debye units) + not polar
76
77
78
79 Dipole Moment A substance possesses a dipole moment if its centers of positive and negative charge do not coincide. m= e x d (expressed in Debye units) + polar
80 Molecular Dipole Moments d- d+ d- O C O molecule must have polar bonds necessary, but not sufficient need to know molecular shape because individual bond dipoles can cancel
81 Molecular Dipole Moments O C O Carbon dioxide has no dipole moment; m= = 0 D
82 Comparison of Dipole Moments Carbon tetrachloride m= = 0 D Dichloromethane m= = 1.62 D
83 Carbon tetrachloride Resultant of these two bond dipoles is Resultant of these two bond dipoles is m= = 0 D Carbon tetrachloride has no dipole moment because all of the individual bond dipoles cancel.
84 Dichloromethane Resultant of these two bond dipoles is Resultant of these two bond dipoles is m= = 1.62 D The individual bond dipoles do not cancel in dichloromethane; it has a dipole moment.
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
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
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.
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
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.
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
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
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,
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,
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
A REVIEW OF GENERAL CHEMISTRY: ELECTRONS, BONDS AND MOLECULAR PROPERTIES
A REVIEW OF GENERAL CEMISTRY: ELECTRONS, BONDS AND MOLECULAR PROPERTIES A STUDENT SOULD BE ABLE TO: 1. Draw Lewis (electron dot and line) structural formulas for simple compounds and ions from molecular
Worksheet 14 - Lewis structures. 1. Complete the Lewis dot symbols for the oxygen atoms below
Worksheet 14 - Lewis structures Determine the Lewis structure of 2 oxygen gas. 1. omplete the Lewis dot symbols for the oxygen atoms below 2. Determine the number of valence electrons available in the
The elements of the second row fulfill the octet rule by sharing eight electrons, thus acquiring the electronic configuration of neon, the noble gas o
2. VALENT BNDING, TET RULE, PLARITY, AND BASI TYPES F FRMULAS LEARNING BJETIVES To introduce the basic principles of covalent bonding, different types of molecular representations, bond polarity and its
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
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
Chem 121 Problem Set V Lewis Structures, VSEPR and Polarity
hemistry 121 Problem set V olutions - 1 hem 121 Problem et V Lewis tructures, VEPR and Polarity AWER 1. pecies Elecronegativity difference in bond Bond Polarity Mp 3 E = 3.0-3.0 = 0 for - very weakly polar
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
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
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
2. Which one of the ions below possesses a noble gas configuration? A) Fe 3+ B) Sn 2+ C) Ni 2+ D) Ti 4+ E) Cr 3+
Chapter 9 Tro 1. Bromine tends to form simple ions which have the electronic configuration of a noble gas. What is the electronic configuration of the noble gas which the bromide ion mimics? A) 1s 2 2s
C has 4 valence electrons, O has six electrons. The total number of electrons is 4 + 2(6) = 16.
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
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
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
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
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
CHAPTER 6 REVIEW. Chemical Bonding. Answer the following questions in the space provided.
Name Date lass APTER 6 REVIEW hemical Bonding SETIN 1 SRT ANSWER Answer the following questions in the space provided. 1. a A chemical bond between atoms results from the attraction between the valence
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
Sample Exercise 8.1 Magnitudes of Lattice Energies
Sample Exercise 8.1 Magnitudes of Lattice Energies Without consulting Table 8.2, arrange the ionic compounds NaF, CsI, and CaO in order of increasing lattice energy. Analyze From the formulas for three
: : Solutions to Additional Bonding Problems
Solutions to Additional Bonding Problems 1 1. For the following examples, the valence electron count is placed in parentheses after the empirical formula and only the resonance structures that satisfy
CHAPTER 12: CHEMICAL BONDING
CHAPTER 12: CHEMICAL BONDING Active Learning Questions: 3-9, 11-19, 21-22 End-of-Chapter Problems: 1-36, 41-59, 60(a,b), 61(b,d), 62(a,b), 64-77, 79-89, 92-101, 106-109, 112, 115-119 An American chemist
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.
SOME TOUGH COLLEGE PROBLEMS! .. : 4. How many electrons should be shown in the Lewis dot structure for carbon monoxide? N O O
SME TUGH CLLEGE PRBLEMS! LEWIS DT STRUCTURES 1. An acceptable Lewis dot structure for 2 is (A) (B) (C) 2. Which molecule contains one unshared pair of valence electrons? (A) H 2 (B) H 3 (C) CH 4 acl 3.
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.
1.2 CLASSICAL THEORIES OF CHEMICAL BONDING
1. CLASSICAL TEORIES OF CEMICAL BONDING simply memorizing them. We ll consider some of the organic chemistry that is industrially important. Finally, we ll examine some of the beautiful applications of
Sample Exercise 8.1 Magnitudes of Lattice Energies
Sample Exercise 8.1 Magnitudes of Lattice Energies Without consulting Table 8.2, arrange the following ionic compounds in order of increasing lattice energy: NaF, CsI, and CaO. Analyze: From the formulas
Structure, Polarity & Physical Properties
tructure, Polarity & Physical Properties upplemental packet handouts 92-96 I. Lewis structure, stability, and bond energies A. ydrogen, oxygen, and nitrogen are present in the atmosphere as diatomic molecular
Chapter 1 Structure and Bonding. Modified by Dr. Daniela Radu
John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 1 Structure and Bonding Modified by Dr. Daniela Radu What is Organic Chemistry? Living things are made of organic chemicals Proteins that make
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
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
Lewis Dot Notation Ionic Bonds Covalent Bonds Polar Covalent Bonds Lewis Dot Notation Revisited Resonance
Lewis Dot Notation Ionic Bonds Covalent Bonds Polar Covalent Bonds Lewis Dot Notation Revisited Resonance Lewis Dot notation is a way of describing the outer shell (also called the valence shell) of an
Ionic and Covalent Bonds
Ionic and Covalent Bonds Ionic Bonds Transfer of Electrons When metals bond with nonmetals, electrons are from the metal to the nonmetal The becomes a cation and the becomes an anion. The between the cation
7) How many electrons are in the second energy level for an atom of N? A) 5 B) 6 C) 4 D) 8
HOMEWORK CHEM 107 Chapter 3 Compounds Putting Particles Together 3.1 Multiple-Choice 1) How many electrons are in the highest energy level of sulfur? A) 2 B) 4 C) 6 D) 8 2) An atom of phosphorous has how
Questions on Chapter 8 Basic Concepts of Chemical Bonding
Questions on Chapter 8 Basic Concepts of Chemical Bonding Circle the Correct Answer: 1) Which ion below has a noble gas electron configuration? A) Li 2+ B) Be 2+ C) B2+ D) C2+ E) N 2-2) Of the ions below,
CHEM 1301 SECOND TEST REVIEW. Covalent bonds are sharing of electrons (ALWAYS valence electrons). Use Lewis structures to show this sharing.
CEM 1301 SECOND TEST REVIEW Lewis Structures Covalent bonds are sharing of electrons (ALWAYS valence electrons). Use Lewis structures to show this sharing. Rules OCTET RULE an atom would like to have 8
Chemistry 105, Chapter 7 Exercises
hemistry 15, hapter 7 Exercises Types of Bonds 1. Using the periodic table classify the bonds in the following compounds as ionic or covalent. If covalent, classify the bond as polar or not. Mg2 4 i2 a(3)2
A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together is called a(n)
Chemistry I ATOMIC BONDING PRACTICE QUIZ Mr. Scott Select the best answer. 1) A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together is
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
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
Chapter 8 Concepts of Chemical Bonding
Chapter 8 Concepts of Chemical Bonding Chemical Bonds Three types: Ionic Electrostatic attraction between ions Covalent Sharing of electrons Metallic Metal atoms bonded to several other atoms Ionic Bonding
OCTET RULE Generally atoms prefer electron configurations with 8 valence electrons. - Filled s and p subshells
TYPES EMIAL BDIG 1 Ionic Bonding - Bond between ions whose charges attract each other - ne atom gives electrons and one atom takes electrons. Example a + l - ionic bond ovalent Bonding - two atoms each
We will not be doing these type of calculations however, if interested then can read on your own
Chemical Bond Lattice Energies and Types of Ions Na (s) + 1/2Cl 2 (g) NaCl (s) ΔH= -411 kj/mol Energetically favored: lower energy Like a car rolling down a hill We will not be doing these type of calculations
4.2. Molecular Shape and Polarity. Lewis Structures for Molecules and Polyatomic Ions
Molecular Shape and Polarity 4.2 molecule is a discrete chemical entity, in which atoms are held together by the electrostatic attractions of covalent bonds. In previous chemistry courses, you used Lewis
Chapter 10 Molecular Geometry and Chemical Bonding Theory
Chem 1: Chapter 10 Page 1 Chapter 10 Molecular Geometry and Chemical Bonding Theory I) VSEPR Model Valence-Shell Electron-Pair Repulsion Model A) Model predicts Predicts electron arrangement and molecular
Which substance contains positive ions immersed in a sea of mobile electrons? A) O2(s) B) Cu(s) C) CuO(s) D) SiO2(s)
BONDING MIDTERM REVIEW 7546-1 - Page 1 1) Which substance contains positive ions immersed in a sea of mobile electrons? A) O2(s) B) Cu(s) C) CuO(s) D) SiO2(s) 2) The bond between hydrogen and oxygen in
Chapter 2 The Chemical Context of Life
Chapter 2 The Chemical Context of Life Multiple-Choice Questions 1) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living
LEWIS DIAGRAMS. by DR. STEPHEN THOMPSON MR. JOE STALEY
by DR. STEPHEN THOMPSON MR. JOE STALEY The contents of this module were developed under grant award # P116B-001338 from the Fund for the Improvement of Postsecondary Education (FIPSE), United States Department
pre -TEST Big Idea 2 Chapters 8, 9, 10
Name: AP Chemistry Period: Date: R.F. Mandes, PhD, NBCT Complete each table with the appropriate information. Compound IMF Compound IMF 1 NiCl 3 7 ClCH 2 (CH 2 ) 3 CH 3 2 Fe 8 H 2 CF 2 3 Ar 9 H 2 NCH 2
Chapter 2 Polar Covalent Bonds: Acids and Bases
John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds: Acids and Bases Modified by Dr. Daniela R. Radu Why This Chapter? Description of basic ways chemists account for chemical
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
Chapter 9. Chemical reactivity of molecules depends on the nature of the bonds between the atoms as well on its 3D structure
Chapter 9 Molecular Geometry & Bonding Theories I) Molecular Geometry (Shapes) Chemical reactivity of molecules depends on the nature of the bonds between the atoms as well on its 3D structure Molecular
Exercises Topic 2: Molecules
hemistry for Biomedical Engineering. Exercises Topic 2 Authors: ors: Juan Baselga & María González Exercises Topic 2: Molecules 1. Using hybridization concepts and VSEPR model describe the molecular geometry
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
Bonding Practice Problems
NAME 1. When compared to H 2 S, H 2 O has a higher 8. Given the Lewis electron-dot diagram: boiling point because H 2 O contains stronger metallic bonds covalent bonds ionic bonds hydrogen bonds 2. Which
3/5/2014. iclicker Participation Question: A. MgS < AlP < NaCl B. MgS < NaCl < AlP C. NaCl < AlP < MgS D. NaCl < MgS < AlP
Today: Ionic Bonding vs. Covalent Bonding Strengths of Covalent Bonds: Bond Energy Diagrams Bond Polarities: Nonpolar Covalent vs. Polar Covalent vs. Ionic Electronegativity Differences Dipole Moments
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
Section Activity #1: Fill out the following table for biology s most common elements assuming that each atom is neutrally charged.
LS1a Fall 2014 Section Week #1 I. Valence Electrons and Bonding The number of valence (outer shell) electrons in an atom determines how many bonds it can form. Knowing the number of valence electrons present
Chapter 4: Structure and Properties of Ionic and Covalent Compounds
Chapter 4: Structure and Properties of Ionic and Covalent Compounds 4.1 Chemical Bonding o Chemical Bond - the force of attraction between any two atoms in a compound. o Interactions involving valence
PRACTICE PROBLEMS, CHAPTERS 1-3
PRATIE PRBLEMS, APTERS 1-3 (overed from h. 3: Alkane and Alkyl alide nomenclature only) 1. The atomic number of boron is 5. The correct electronic configuration of boron is: A. 1s 2 2s 3 B. 1s 2 2p 3.
Molecular Geometry & Polarity
Name AP Chemistry Molecular Geometry & Polarity Molecular Geometry A key to understanding the wide range of physical and chemical properties of substances is recognizing that atoms combine with other atoms
Formal Charges. Step 2. Assign the formal charge to each atom. Formal charge is calculated using this formula: H O H H
Formal harges Discussion: Ions bear a positive or negative charge. If the ion is polyatomic (is constructed of more than on atom), we might ask which atom(s) of the ion carry the charge? Knowledge of charge
Chapter 2 Polar Covalent Bonds; Acids and Bases
John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds; Acids and Bases Javier E. Horta, M.D., Ph.D. University of Massachusetts Lowell Polar Covalent Bonds: Electronegativity
Exam 2 Chemistry 65 Summer 2015. Score:
Name: Exam 2 Chemistry 65 Summer 2015 Score: Instructions: Clearly circle the one best answer 1. Valence electrons are electrons located A) in the outermost energy level of an atom. B) in the nucleus of
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
CHEMISTRY 1710 - Practice Exam #5 - SPRING 2014 (KATZ)
CHEMISTRY 1710 - Practice Exam #5 - SPRING 2014 (KATZ) Name: Score: This is a multiple choice exam. Choose the BEST answer from the choices which are given and write the letter for your choice in the space
Ionization energy _decreases from the top to the bottom in a group. Electron affinity increases from the left to the right within a period.
hem 150 Answer Key roblem et 2 1. omplete the following phrases: Ionization energy _decreases from the top to the bottom in a group. Electron affinity increases from the left to the right within a period.
Type of Chemical Bonds
Type of Chemical Bonds Covalent bond Polar Covalent bond Ionic bond Hydrogen bond Metallic bond Van der Waals bonds. Covalent Bonds Covalent bond: bond in which one or more pairs of electrons are shared
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
Chemistry 5.12 Spring 2003 Lectures #1 & 2, 2/5,7/03. Outline
hemistry 5.12 Spring 2003 Lectures #1 & 2, 2/5,7/03 utline Discuss General lass Information (Professor Imperiali) General Introduction to rganic hemistry I. Review of Lewis Bonding Theory (Read hapter
Unit 3: Quantum Theory, Periodicity and Chemical Bonding. Chapter 10: Chemical Bonding II Molecular Geometry & Intermolecular Forces
onour Chemistry Unit 3: Quantum Theory, Periodicity and Chemical Bonding Chapter 10: Chemical Bonding II Molecular Geometry & Intermolecular orces 10.1: Molecular Geometry Molecular Structure: - the three-dimensional
Chapter 8 Basic Concepts of the Chemical Bonding
Chapter 8 Basic Concepts of the Chemical Bonding 1. There are paired and unpaired electrons in the Lewis symbol for a phosphorus atom. (a). 4, 2 (b). 2, 4 (c). 4, 3 (d). 2, 3 Explanation: Read the question
In the box below, draw the Lewis electron-dot structure for the compound formed from magnesium and oxygen. [Include any charges or partial charges.
Name: 1) Which molecule is nonpolar and has a symmetrical shape? A) NH3 B) H2O C) HCl D) CH4 7222-1 - Page 1 2) When ammonium chloride crystals are dissolved in water, the temperature of the water decreases.
CHEM 1211K Test IV. MULTIPLE CHOICE (3 points each)
CEM 1211K Test IV MULTIPLE COICE (3 points each) 1) ow many single covalent bonds must a silicon atom form to have a complete octet in its valence shell? A) 4 B) 3 C) 1 D) 2 E) 0 2) What is the maximum
List the 3 main types of subatomic particles and indicate the mass and electrical charge of each.
Basic Chemistry Why do we study chemistry in a biology course? All living organisms are composed of chemicals. To understand life, we must understand the structure, function, and properties of the chemicals
Bonds. Bond Length. Forces that hold groups of atoms together and make them function as a unit. Bond Energy. Chapter 8. Bonding: General Concepts
Bonds hapter 8 Bonding: General oncepts Forces that hold groups of atoms together and make them function as a unit. Bond Energy Bond Length It is the energy required to break a bond. The distance where
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
Chapter 8: Covalent Bonding and Molecular Structure
hapter 8 ovalent Bonding and Molecular Structure 8-1 hapter 8: ovalent Bonding and Molecular Structure hapter 8 8.1 Interactions Between Particles: oulomb s Law 8.2 ovalent Bonding Basics 8.3 Lewis Structures
The Lewis structure is a model that gives a description of where the atoms, charges, bonds, and lone pairs of electrons, may be found.
CEM110 Week 12 Notes (Chemical Bonding) Page 1 of 8 To help understand molecules (or radicals or ions), VSEPR shapes, and properties (such as polarity and bond length), we will draw the Lewis (or electron
CHAPTER 6 Chemical Bonding
CHAPTER 6 Chemical Bonding SECTION 1 Introduction to Chemical Bonding OBJECTIVES 1. Define Chemical bond. 2. Explain why most atoms form chemical bonds. 3. Describe ionic and covalent bonding.. 4. Explain
3) Of the following, radiation has the shortest wavelength. A) X-ray B) radio C) microwave D) ultraviolet E) infrared Answer: A
1) Which one of the following is correct? A) ν + λ = c B) ν λ = c C) ν = cλ D) λ = c ν E) νλ = c Answer: E 2) The wavelength of light emitted from a traffic light having a frequency of 5.75 1014 Hz is.
A PREVIEW & SUMMMARY of the 3 main types of bond:
Chemical Bonding Part 1 Covalent Bonding Types of Chemical Bonds Covalent Bonds Single Polar Double NonPolar Triple Ionic Bonds Metallic Bonds Other Bonds InterMolecular orces first A PREVIEW & SUMMMARY
1.3 STRUCTURES OF COVALENT COMPOUNDS
1.3 STRUTURES OF OVALENT OMPOUNDS 13 1.9 Draw an appropriate bond dipole for the carbon magnesium bond of dimethylmagnesium. Explain your reasoning. 3 Mg 3 dimethylmagnesium 1.3 STRUTURES OF OVALENT OMPOUNDS
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
Chapter 4 Lecture Notes
Chapter 4 Lecture Notes Chapter 4 Educational Goals 1. Given the formula of a molecule, the student will be able to draw the line-bond (Lewis) structure. 2. Understand and construct condensed structural
19.1 Bonding and Molecules
Most of the matter around you and inside of you is in the form of compounds. For example, your body is about 80 percent water. You learned in the last unit that water, H 2 O, is made up of hydrogen and
AP* Bonding & Molecular Structure Free Response Questions page 1
AP* Bonding & Molecular Structure ree Response Questions page 1 (1) AP is a registered trademark of the ollege Board. The ollege Board was not involved in the production of and does not endorse this product.
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
Unit 3: Quantum Theory, Periodicity and Chemical Bonding
Selected Honour Chemistry Assignment Answers pg. 9 Unit 3: Quantum Theory, Periodicity and Chemical Bonding Chapter 7: The Electronic Structure of Atoms (pg. 240 to 241) 48. The shape of an s-orbital is
O P O O. This structure puts the negative charges on the more electronegative element which is preferred. Molecular Geometry: O Xe O
hemistry& 141 lark ollege Exam 4 olution 1. Draw the Lewis structures for the following molecules and ions. Include formal charges and resonance structures, where appropriate. Fill out the table for the
Molecular Structures. Chapter 9 Molecular Structures. Using Molecular Models. Using Molecular Models. C 2 H 6 O structural isomers: .. H C C O..
John W. Moore onrad L. Stanitski Peter. Jurs http://academic.cengage.com/chemistry/moore hapter 9 Molecular Structures Stephen. oster Mississippi State University Molecular Structures 2 6 structural isomers:
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,