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Unformatted text preview: This is an information and scratch paper page. Nothing on this page will be graded. It will be discarded prior to grading. You may **carefully** remove it from the exam. You do not need to turn in this page. (+)-Abscisic acid is a hormone produced by plants when growth conditions are unfavorable. Its presence inhibits growth, conserves water, and in general tells the plant to slow down. Pyrabactin is a synthetic product which mimics the action of (+)-abscisic acid, and as has been used in agriculture as a weed growth inhibitor. (+)-Abscisic acid Pyrabactin OH O CH 3 CH 3 OH O S O O N N Br H Pyridine ring Chemistry 14C Winter 2012 Midterm Exam 1 Page 1 Page 1 score = 1. (2) Write the molecular formula of (+)-abscisic acid (i.e. C 4 H 60 ). 2. (4) Write the names of all functional groups present in (+)-abscisic acid. 3. (4) Write a number in each blank: (+)-Abscisic acid has ___________ sp 2 atoms and ___________ lone pairs. 4. (8) Biological properties of molecules are often influenced by how much they ionize in aqueous solution. In the case of (+)-abscisic acid, this ionization is strongly influenced by resonance. (a) In boxes B and C draw two additional resonance contributors of structure A . ( means molecule beyond this point not important.) Less significant resonance contributors will earn less significant credit . Include all lone pairs and nonzero formal charges. A B C (b) In boxes E and F draw two additional resonance contributors of structure D . Less significant resonance contributors will earn less significant credit . Include all lone pairs and nonzero formal charges. D E F 5. (7) Consider the relative significance of resonance contributors D F of question 4(b). In each statement below write is or is not in each blank as appropriate to complete each statement. If you write is not complete the explanation by adding...
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This note was uploaded on 02/13/2012 for the course CHEMISTRY 14C taught by Professor Hardinger during the Spring '06 term at UCLA.
- Spring '06