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 ybridization Orbital Diagram of central atom alone b) ClNO ybridization Orbital Diagram of central atom alone
c) PF 6 ybridization Orbital Diagram of central atom alone (P ): add one electron d) TeCl 2 Br 2 ybridization Orbital Diagram of central atom alone
e) NO 2 ybridization Orbital Diagram of central atom alone 2. a. Draw the Lewis structure of acetone, (C 3 ) 2 CO (C in the middle, with two C s and an O bonded to it). What is the hybridization on each carbon atom in the molecule? b. On the Lewis structure, identify the type of each bond (σ or π). c. Describe the orbital location, including type of bond, of each pair of electrons in the molecule including lone pairs (for example, there are six pairs of electrons in six different σ bonds formed between an s orbital on a hydrogen and an sp 3 hybrid orbital in a carbon).
3. Draw the Lewis structure and determine the hybridization on the central atom in each of the following molecules. Then draw the orbital diagrams of the central atom alone, and the central atom in the molecule. a. BrF 3 b. XeF 4 c. CN 4. Epinephrine, also called adrenaline, is a hormone and a neurotransmitter that, among other things, is involved in the fight or flight response. The structure of epinephrine, with some atoms labeled with numbers, is shown below. This representation does not show any lone pairs of electrons, but all oxygen atoms with two bonds should have two lone pairs and nitrogen atoms with three bonds should have one lone pair. This structure also does not show all bonds. For the oxygen atom labeled 1, it has one bond to carbon #2 and one bond to hydrogen. The carbon labeled number 5 has one bond to nitrogen #4 and three bonds to three hydrogen atoms. a. For each of the labeled atoms, identify the shape around that atom, the bond angle, and the hybridization on that atom. b. ow many π bonds are in this structure?
Answer Key 1. a. molecular geometry: tetrahedral bond angle: 109.5º polar sp 3 hybridized Cl C Cl C alone C in CCl 2 2 2s sp 3 b. molecular geometry: bent bond angle: <120º polar sp 2 hybridized N alone Cl N O N in ClNO sp 2 2s c. molecular geometry: octahedral bond angle: 90º nonpolar sp 3 d 2 hybridized
P alone P in PF 6 3d 3d 3p sp 3 d 2 3s d. molecular geometry: seew saw (Br atoms are larger, so they will be in equatorial positions) bond angle: <90º and <120º polar sp 3 d hybridized e. Te alone Te in TeCl 2 Br 2 5d 5d 5p sp 3 d 5s f. electron pair geometry: trigonal planar molecular geometry: bent bond angle: <120º polar sp 2 hybridized O N O O N O N alone N in NO 2 2s sp 2
2. sp 3 O sp 3 C C C sp 2 There are six pairs of electrons in six different σ bonds formed between an s orbital on a hydrogen and an sp 3 hybrid orbital in a carbon. There are two pairs of electrons in two bonds formed between an sp 3 hybrid orbitals on the outside carbons and an sp 2 hybrid orbital on the central carbon. There is one pair of electrons in a σ bond between an sp 2 hybrid orbital on the central carbon and an sp 2 hybrid orbital on the oxygen. There is one pair of electrons in a π bond between the orbital on the central carbon and the orbital of the oxygen. There are two lone pairs of electrons in sp 2 hybid orbitals of the oxygen. 3. a. Lewis structure is below. Br is sp 3 d hybridized. Orbital diagrams are below. Br alone Br in BrF 3 4d 4d 4p sp 3 d 4s b. Lewis structure is below. Xe is sp 3 d 2 hybridized. Orbital diagrams are below.
Xe alone Xe in XeF 4 5d 5d 5p sp 3 d 5s c. Lewis structure is below. C is sp 2 hybridized. Orbital diagrams are below. C alone C in CN sp 2s 4. O 1: bent, <109.5º, sp 3 C 2 : trigonal planar, 120º, sp 2 C 3 : tetrahedral, 109.5º, sp 3 N 4 : trigonal pyramidal, <109.5º, sp 3 C 5 : tetrahedral, 109.5º, sp 3