Announcements Be respectful – no electronics please! **Please have your lab book out and open to page 70 if you have it with you.** Lab & Textbook homework due tomorrow in discussion Pre-lecture Assignments Due Tues/Thurs at 8 am HW 7 Due Wednesday at 8 am Exam 3 is on Thursday April 25 at 7 pm! The final exam is on Thursday May 9 at 1:30 pm!
Chem 101: Last 4 Weeks Calendar Monday Tuesday Wednesday Thursday Friday 8 9 10 11 12 15 16 17 18 19 22 23 24 25 26 29 30 1 2 3 6 7 Today Exam 3 Reading Day 101A Final
Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure Molecular Properties
Clicker #1 Which of the following supports why Lewis structures are not a completely accurate way to draw molecules? A) The Lewis structure for O2 shows all electrons as paired but when liquid O2 is poured onto a magnet, it behaves as a molecule with an unpaired electron. B) There are sometimes multiple valid Lewis structures for a single chemical species known as resonance structures. C) When adding up the number of valence electrons for a molecule (such as nitrogen monoxide), it is possible to get an odd number which would make it impossible to satisfy the octet rule for all atoms. D) All of the above statements support why Lewis structures are not a completely accurate way to draw molecules. E) Lewis structures are the most accurate way to draw molecules and are completely correct.
Overall goal: Atomic Structure Chemical Bonding 3D Molecular Structure Molecular Properties
Pages 70 and 71 in Lab Book
CO2 SO2 H2O
Chem 101: Last 4 Weeks Calendar Monday Tuesday Wednesday Thursday Friday 8 9 10 11 12 15 16 17 18 19 22 23 24 25 26 29 30 1 2 3 6 7 Today Exam 3 Reading Day 101A Final
Clicker #2 Draw the Lewis structure for PCl3. What are the geometry, shape, and bond angles of this molecule? Geometry Shape Bond Angles a) Trigonal planar 120° b) Tetrahedral 109.5° c) Trigonal pyramid 107° d) e)
PCl3
Polar vs. Nonpolar Molecules CO2 HCN
Polar vs. Nonpolar Molecules BH3 CH2O
Polar vs. Nonpolar Molecules CH4 CH2F2
Check-In Does H2O have an overall net dipole moment (is it polar overall)? 1) Yes, the electrons are found more towards hydrogen atoms. 2) Yes, the electrons are found more towards the oxygen atom. 3) No, the electron distribution is symmetrical around the central atom.
Check-In Does PCl3 have an overall net dipole moment (is it polar overall)? 1) Yes, the electrons are found more towards chlorine atoms. 2) Yes, the electrons are found more towards the phosphorus. 3) No, the electron distribution is symmetrical around the central atom.
Check-In Does SO3 have an overall net dipole moment (is it polar overall)? 1) Yes, the electrons are found more towards oxygen. 2) Yes, the electrons are found more towards the sulfur. 3) No, the electron distribution is symmetrical around the central atom.
Clicker #3 Draw the Lewis structure for CH4. What are the geometry, shape, bond angles, and polarity of this molecule? Geometry Shape Bond Angles Polar? a) Tetrahedral 109.5° Polar b) Nonpolar c) Trigonal pyramid 107° d)
Clicker #4 Draw the Lewis structure for CH3F. What are the geometry, shape, bond angles, and polarity of this molecule? Geometry Shape Bond Angles Polar? a) Tetrahedral 109.5° Polar b) Nonpolar c) Trigonal pyramid 107° d)