Chemistry Problems

Problem #1 Draw Lewis structures for each of the following ions. Indicate all formal charges, and show all resonance forms, if any. a) the CH1O cation b) the N3 anion c) the C3H3 anion (all three H atoms are on the same carbon) Problem #2 Nocardicin A, shown below, is a monocyclic B-lactam with antimicrobial activity similar to penicillin. Circle and label 5 different functional groups present in Nocardicin A. .OH N H OH NH2 Il HO. o N o o o COH Problem #3 Draw all valid resonance contributors for the following cation. Show how the electrons can be moved using curved-arrow notation. CH3 o CH3 Problem #4 The molecule shown below is an example of an allene. a) What is the geometry about each carbon? b) What is the hybridization for each carbon? H c) How many a-bonds and n-bonds are in the molecule? Extra Credit The following compound has two configurational isomers: CICH-CHCI One isomer has no dipole moment ( 0 Debyes), while the other has a relatively large dipole (II - 2.95 D). Propose structures for the two isomers that are consistent with these data.