Lewis Structures and Molecular Geometry

Slides:

Advertisements

Similar presentations

IIIIII IV. Lewis Diagrams (p. 170 – 175) Unit 6 – Molecular Structure.

Advertisements

IIIIII Lewis Diagrams (p. 170 – 175) Ch. 6 – Molecular Structure.

Lewis Dot Structures Dots are arranged around an element’s symbol to indicate the valence electrons Reminder: valence shell only has s & p orbitals  maximum.

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

Drawing Lewis Structures and VSEPR. Draw basic Lewis dot structures of atoms and compounds. Using VSEPR, predict bond shape from electron arrangement.

Cl Cl Br Br I I #7 Draw electron dot structures for each molecule

1 Drawing Lewis Structures A step-by-step guide See page 305.

Sections 8.1 – 8.2 Bonding in Covalent Molecules.

Chemical Bonding: The Covalent Bond Model. Chemical Bonds Forces that hold atoms to each other within a molecule or compound.

More Lewis Structures Lewis Dot Structures. Total Number of Valence Electrons The total number of available valence electrons is just the sum of the number.

-Types of Covalent Bonds -Rules for Writing Lewis Dot Structures of Molecular Compounds Chemistry Mrs. Coyle.

Chemical Bonding © 2009, Prentice-Hall, Inc. Polar Covalent Bonds The greater the difference in electronegativity, the more polar is the bond.

Lewis Dot Structures Quick Review.

Electron Dot and Structual Diagrams for Covalent Compounds.

Lewis Diagrams.

Chapter 5 Compounds and Their Bonds

Daily Science Name the following: HBr H 2 SO 3 P 3 O 5 Label the following as being an ionic bond or covalent bond: NaCl Iron (III) oxide Dinitrogen pentoxide.

1 Molecular Geometry and Polarity Part B: Lewis Structure Dr. Chin Chu River Dell Regional High School.

Drawing Lewis Structures of Molecules Chapter 4 Section 4.

Lewis Structures Electron-Dot-Diagrams For Molecules.

Lewis Structures ©2011 University of Illinois Board of Trustees

8.4 DETERMINING MOLECULAR SHAPES. THE MODEL WE WILL USE TO DETERMINE MOLECULAR SHAPE IS CALLED _________ (V_____________ S_________ E_____________ P________.

Molecular Structure Part I: Lewis Diagrams

Lewis Structures & Molecular Geometries. Why Compounds Form Nobel gases do not form bonds because they have completely filled energy levels and do not.

Drawing Lewis Structures and predicting formulas of covalent compounds.

IIIIII I. Lewis Diagrams Ch. 9 – Molecular Structure C. Johannesson.

Rules For Lewis Structures (Pre- AP) Adapted from Brown and Lemay.

IIIIII I. Lewis Diagrams Molecular Structure. A. Octet Rule n Remember…  Most atoms form bonds in order to have 8 valence electrons.

LEWIS STRUCTURES. How to draw Lewis structures for Neutral molecules 1. Determine the total valence electrons for the molecule. Find the # of valence.

IIIIII C. Johannesson I. Lewis Diagrams (p. 170 – 175) Ch. 6 – Molecular Structure.

Tuesday 10/19/10.  Return Naming Compounds Quiz  Collect Symbol Me Projects  Lewis structures  Metallic Bonding  Hydrogen Bonding  Jeopardy Review.

Writing Lewis Structure. Steps 1.Count the total number of valence electrons a.Add one for each negative charge b.Subtract one for each positive charge.

Electron-Dot Model of Bonding: Lewis Structures Lewis structures are drawn by following simple rules. 1.Draw the molecular skeleton 2.Count the number.

Lewis Structures for Molecular Compounds

Chemical Bonding Molecular Polarity Vector Sum of Bond Polarities Why are some molecules polar but others are not?

 LEM › A molecule is composed of atoms that are bound together by sharing pairs of e- using the atomic orbitals of the bound atoms. › Lone pairs › Bonding.

Bonding and Structure 1 Chemical Bonding and Molecular Structure Ionic vs. covalent bonding Molecular orbitals and the covalent bond Valence electron Lewis.

LEWIS DOT STRUCTURES Arrange the symbols such that the least electronegative element is in the center and the other elements are surrounding the.

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.

Drawing Lewis Structures of Molecules Chapter 4 Section 4.

Can you draw the lewis structures for the following compounds?

Covalent Bonding Diagrams

Electron Dot and Structual Diagrams for Covalent Compounds

Covalent bonding & Lewis Structures

Chapter 6-2 Lewis Structures (p. 206 – 207).

Covalent Bonds Covalent bond is a bond formed when 2 electrons are shared between atoms H + H forms H2 Lewis Structure of H2 Lewis Structure of F2 A lone.

Covalent Bonding & Lewis Structures

Chapter 8 Section 3 Molecular Structures.

Unit 6 – Molecular Structure

Ch. 9 – Molecular Structure

Drawing Lewis Structures (electron dot diagrams)

Covalent Bonding.

Molecular Structure Lewis Diagrams (p. 170 – 175).

Sections 8.1 – 8.2 Bonding in Covalent Molecules

GEOMETRY AND POLARITY OF MOLECULES

Chapter 10 Molecular Structure: Solids and Liquids

Why do atoms form chemical bonds?

Molecular Structure and Shape

Writing Lewis Structures

Molecular shapes.

Ch. 6 – Molecular Structure

I. Lewis Diagrams (p. 202 – 213) Lecture 2.

Bellwork Friday Draw Lewis structures for atoms of magnesium and sulfur. Show how these atoms could combine to form a compound using the Lewis structures.

Valence Shell Electrons are all that matter in bonding.

I. Lewis Diagrams (p. 202 – 213) Lecture 2.

Ch. 6 – Molecular Structure

Lewis Structures.

8.5 Lewis Structures Honors Chemistry 2019.

Presentation transcript:

Lewis Structures and Molecular Geometry

Drawing Lewis Structures A recommended procedure : Count the total number of valence electrons (VSE) for the atoms (based on the column of the atom in the periodic table) and charge. (add one electron for each negative charge; subtract one electron for each positive charge). HCN = 1+ 4+ 5 -0 = 10 VSE = 5 VSE pairs C2H6O = 2(4) + 6(1) + 6(1) -0 = 20 VSE = 10 VSE pairs CO32- = 4 + 3(6) + 2 = 24 VSE = 12 VSE pairs

Drawing Lewis Structures Draw the framework with single bonds. Some knowledge of the way the atoms are connected may be required. H C N Complete octets around all the atoms. Exceptions: H only has one pair of electrons, Be only has two and B has only three pairs.

Drawing Lewis Structures Count the number of pairs of electrons depicted. If this number is less than the total, add electrons to the central atom until the total number of electrons is correct. H C N There are 7 pairs in the drawing and there should only be five. Unshared pairs are non-bonding electrons

Drawing Lewis Structures If there are extra pairs of electron in the drawing use lone-pairs (non- bonding pairs) to make double or triple bonds and reduce the total number of electron pairs. H C N  H C N  H C N  H C N Two unshared pairs = one bonded pair

Drawing Lewis Structures Draw the Lewis structure for PCl5 VSE = P (5) and Cl (7x5) = 40 e-, or 20 pairs of electrons. Place P in the center because it is a singleton, and the chlorines around it. Give each Cl an octet and count the pairs. P has more than four pairs called an expanded octet.

Phosphorus Pentachloride

Review: Lewis structures are a 2 dimensional picture of the arrangement of atoms in a molecule. The total pairs of electrons must be correct in your final drawing. Each atom must have four pairs (an octet) of electrons, except H, Be and B. Some atoms may have more than four pairs, like the second row p orbitals.

Lewis Structures Practice Draw Lewis Structure for the following compounds. CO2 7. NO3- H2O 8. SO2 CH4 9. NH3 BeCl2 10. NH4+ PO43- PCl6-