FINAL-key - Sessler CH310M/CH318M SP11 Final Exam Please...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Sessler CH310M/CH318M SP11 Final Exam Initials______ 1 Please circle the section in which you are enrolled: 310M 318M K E Y Please write the first three letters of your last name in the above boxes Organic Chemistry I Final Exam Dr. Jonathan L. Sessler - CH310M/CH318M May 11th, 2011 Name:_______________________________ UT EID:______________________________ Signature:____________________________
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sessler CH310M/CH318M SP11 Final Exam Initials______ 2 1. For the following molecule ( 1 ): (25 points) 1 a. Draw the Lewis dot structure for 1 b. Sketch the bonding sigma ( σ ) molecular orbitals for 1 c. How many electrons are present in the sigma ( σ ) bonding system of 1 ? 10 d. How many electrons are present in lone pairs of 1 ? 12 Br H H Br C H Br C H Br Br Br C C H H
Background image of page 2
Sessler CH310M/CH318M SP11 Final Exam Initials______ 3 e. How many electrons are in the pi ( π ) system of 1 ? 2 f. Using the scheme provided, shade the orbitals to show bonding ( π ) and antibonding ( π *) molecular orbitals for 1 . Label your orbitals as bonding and antibonding on the lines provided in the left column, and fill in the electrons contained in each orbital on the lines provided in the right column. (6 points) Bonding (B) or Anti-bonding (AB) π -electrons g. Explain in one or two sentences why 1,2-dibromoethylene can exist in a cis form (i.e., 1 ) and a trans form, and why the two forms do not interconvert at room temperature. (4 points) (DO NOT EXCEED THE SPACE GIVEN) There is no free rotation about a double bond at room temperature. ______________________________________________________________________________ E AB B
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sessler CH310M/CH318M SP11 Final Exam Initials______ 4 2. Explain in one or sentences why there is no stereochemical preference in the products of reactions that utilize a carbocation intermediate in one or two sentences. Draw a carbocation intermediate to support your claim. What is the hybridization of the carbon with the positive charge? (10 points) (DO NOT EXCEED THE SPACE GIVEN)
Background image of page 4
Sessler CH310M/CH318M SP11 Final Exam Initials______ 5 3. Below you find the Lewis structure for the squaric acid dianion. (15 points) a. Draw three reasonable resonance structures in the boxes provided including charges and lone pairs. Use curved arrows to show the flow of electrons in each structure. O O O O O O O O O O O O O O O O b. How does the resonance model account for the fact that the lengths of each bond type (C-C and C-O) in this ion are identical? (Only one sentence is necessary – do not exceed the space given.) The four resonance structures in squaric acid show that each bond has double-bond character resulting in every bond being equally long.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/16/2011 for the course CHEM 310M taught by Professor Bocknack during the Spring '09 term at University of Texas.

Page1 / 24

FINAL-key - Sessler CH310M/CH318M SP11 Final Exam Please...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online