Unit3Day2 VandenBout Tuesday October 15 2013 8 17 AM Vanden Bout LaBrake Crawford CH301 WHY IS EVERYTHING SO DIFFERENT Think About Shape UNIT 3 Day 2 CH301 Vanden Bout LaBrake Fall 2013 Important Information EXAM WENT WELL for most If you did poorly on EXAM 1 2 PLEASE TALK TO LaB or VDB or Cr LM20 DUE TH 9AM Laude LM Lecture 10 11 CH301 Vanden Bout LaBrake Spring 2013 Unit3Day2 VandenBout Page 1 What are we going to learn today Molecular Shape is an Important Predictor of Physical and Chemical Properties Shape Predict Polarity Properties Determine the Molecular Shapes around the Central Atoms in Molecules CH302 Vanden Bout LaBrake Fall 2012 Quiz CLICKER QUESTION 1 Which of the following bonds would have the greatest dipole moment a F F b H H c H C d H Cl e Na Cl CH301 Vanden Bout LaBrake Fall 2013 Compare Ionic to Covalent Compounds Qr Unit3Day2 VandenBout Page 2 CH301 Vanden Bout LaBrake Fall 2013 Shape Matters Go from a 2 dimensional model to a 3 dimensional shape Take a look at Cl2 Take a look at HCl Take a look at CO2 CH301 Vanden Bout LaBrake Fall 2013 Unit3Day2 VandenBout Page 3 GUIDED LEARNING ACTIVITY Study the table on the learning activity With your neighbor s answer the questions Be prepared to share your answer with others in your sector Each sector choose a representative to speak on your behalf CH301 Vanden Bout LaBrake Fall 2013 POLL CLICKER QUESTION 2 According to the data table a BONDING region is a a single bond b a double bond c a triple bond d either a single double or triple bond e a region where there are nonbonding pairs of electrons CH301 Vanden Bout LaBrake Fall 2013 POLL CLICKER QUESTION 3 The bond angles from the data table can be grouped around a 180 120 109 5 a 120 109 5 107 Unit3Day2 VandenBout Page 4 The bond angles from the data table can be grouped around a 180 120 109 5 a 120 109 5 107 a 107 104 5 120 a 109 5 121 1 180 CH301 Vanden Bout LaBrake Fall 2013 POLL CLICKER QUESTION 4 The correlation between the last two columns in the data table is a bonding regions correlates with bond angle b bonding regions nonbonding regions correlates with bond angle c bonding regions nonbonding regions correlates with bond angle d This makes absolutely no sense whatsoever CH301 Vanden Bout LaBrake Fall 2013 Unit3Day2 VandenBout Page 5 SKETCH SHAPES LABEL SHAPES CH301 Vanden Bout LaBrake Fall 2013 Electron Domains regions Model Balloons Model Supports Bond Angle Data Nonbonding Electron Domain one balloon Single Bond Electron Domain one balloon Double Bond Electron Domain one balloon Triple Bond Electron Domain one balloon Put the domains on a central atom balloon art CH301 Vanden Bout LaBrake Fall 2013 Electron Domains regions Balloons GEOMETRY BOND ANGLE 2 Electron Domains 3 Electron Domains 4 Electron Domains Unit3Day2 VandenBout Page 6 GEOMETRY BOND ANGLE 2 Electron Domains 3 Electron Domains 4 Electron Domains 5 Electron Domains 6 Electron DomainsDomains of electrons around a central atom will orient themselves to minimize the electron electron repulsion between the domains ELECTRONIC GEOMETRY CH301 Vanden Bout LaBrake Fall 2013 Electron Domains and Bond Angles CH301 Vanden Bout LaBrake Fall 2013 POLL CLICKER QUESTION 5 The number of electron domains for the following molecules CH4 NH3 H2O NO3 CO2 are a 4 4 4 4 4 a 4 4 4 3 2 Unit3Day2 VandenBout Page 7 The number of electron domains for the following molecules CH4 NH3 H2O NO3 CO2 are a 4 4 4 4 4 a 4 4 4 3 2 a 4 3 2 3 2 a 4 3 2 4 2 CH301 Vanden Bout LaBrake Fall 2013 POLL CLICKER QUESTION 6 The bond angles for the following molecules CH4 NH3 H2O NO3 CO2 are a 109 5 109 5 109 5 120 180 a 109 5 107 5 104 5 120 180 CH301 Vanden Bout LaBrake Fall 2013 Unit3Day2 VandenBout Page 8 POLL CLICKER QUESTION 7 Consider a set of molecules with the same number of electron domains electronic geometries such as Methane ammonia and water Explain why the measured bond angles in the molecules are different A Student A s explanation B Student B s explanation C Student C s explanation CH301 Vanden Bout LaBrake Fall 2013 POLL CLICKER QUESTION 8 Considering the possible electron geometries explain why the bond angle in bent molecules can be close to either 109 or 120 A Depends on the number of bonding regions B Depends on the number of nonbonding regions and bonding regions CH301 Vanden Bout LaBrake Fall 2013 Lewis Structures Electronic Domains Molecular Shape Take a Little Moment The names for molecular shapes are based on the position of the atoms in the molecule not on the position ofUnit3Day2 VandenBout the electron Page domains 9 Lewis Structures Electronic Domains Molecular Shape Take a Little Moment The names for molecular shapes are based on the position of the atoms in the molecule not on the position of the electron domains Look at water as an example CH301 Vanden Bout LaBrake Fall 2013 MEMORIZE NAMES OF ELECTRONIC GEOMETRIES AND MOLECULAR GEOMETRIES 5 Regions Trigonal Bipyramidal 6 Regions Octahedral Unit3Day2 VandenBout Page 10 6 Regions Octahedral Names and Shapes of expanded octet in LM20 Jot them down memorize them practice CH301 Vanden Bout LaBrake Fall 2013 Based on what you have learned today Predict the of electron domains electronic geometry bond angles and molecular geometry around each atom with an arrow CH301 Vanden Bout LaBrake Fall 2013 Unit3Day2 VandenBout Page 11 Mini Lesson on Line Drawings Carbons are implied at corners Hydrogens are left off structure CH301 Vanden Bout LaBrake Fall 2013 IMPORTANT TO LEARN TO PREDICT SHAPES SO YOU CAN NEXT PREDICT SYMMETRY THEN PREDICT POLARITY OF COMPOUNDS DOES THE MOLECULE CONTAIN A NET DIPOLE MOMENT CH301 Vanden Bout LaBrake Fall 2013 Unit3Day2 VandenBout Page 12 What have we learned Predict Bond Geometries based on Bond Angles Predict Bond Angles based on electronic geometry and molecular geometry Names of common Electronic Geometries CH301 Vanden Bout LaBrake Fall 2013 Learning Outcomes Apply the VSEPR model to determine a molecule s electronic geometry and molecular geometry from it s Lewis dot structure Interpret line drawing of chemical compounds with implicit hydrogen carbon and lone pairs CH301 Vanden Bout LaBrake Fall 2013 Unit3Day2 VandenBout Page 13
View Full Document
Unlocking...