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Chem 2312-003 Midterm I F12 Page 1 of 6

Chemistry 2312-003

Organic Chemistry I

Midterm Examination I

11:00 am 12:20 pm

September 25, 2012

J. Jeon

Name: ____________________________________ Total /100

please print

ID #: ______________________________________

There are 100 points on this exam and the six exam pages. For the multiple choice questions 1-20, select the best answerand darken completelywith

a pencilthe space corresponding to that answer in scantron (form # 882-E).

You are free to use molecular models during the exam.Have fun!

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Chem 2312-003 Midterm I F12 Page 2 of 6

1. (5 pts) Five atoms in the molecule below are labeled as Ato E. Which of the following is correct

regarding i) valence, ii) hybridization, iii) electronic arrangement of the each numbered atom?

B

N

H

H H

E

A

B

C

DO

i) valence ii) hybridizationiii) electronic

arrangement

a) A

b) B

c) C

d) D

e) E

3

3

4

3

3

sp2

sp

sp3

sp2

sp2

bent

linear

trigonal planar

tetrahedral

trigonal planar

2. (5 pts) Which statement concerning the length of bonds indicated in the molecule below is correct?

III

B

N

H

H H

O

II

I

a) II is the shortest and I is the longest

b) II is the shortest and III is the longest

c) III is the shortest and II is the longest

d) III is the shortest and I is the longest

e) I is the shortest and III is the longest

3. (5 pts) The dipole moments (if any) of each of the following molecules are given. Which of the

following is notcorrectly indicated.

a)

F

F

b)

O C O

c)

O

d)

O

4-9. Questions 4/5and 6/7are related to each other.

4. (5 pts) Select the major resonance contributor.

O

N

O

N

1a 1b

Br Br

CH3 CH3

a) 1a

b)1b

c) same

5. (5 pts) Select the best explanation regarding your choice above (1a vs. 1b in question 4).

a) charges b) octet rule c) atom size d) electronegativity e) molecular geometry

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Chem 2312-003 Midterm I F12 Page 4 of 6

11. (5 pts) Select the molecule with the lowest pKa (6a and 6b).

P

H

P

H

vs.

CH3

CH3

CH3

CH3

6a 6b

a) 6a

b)6b

c) same

12. (5 pts) Select the best explanation regarding your choice above (in question 11).

a) electronegativity of atoms b) atom size c) resonance d) inductive effect e) orbitals

13. (5 pts) Acid-base (proton transfer) reaction is shown below. Which of the following statements is

correct?

CH3

O

HO

O

+

O

+

H

H

H

H

H

7 8 9 10

CH3

O

O

a) 8 is acid

b) 10 is base

c) the reactants will be favored at equilibrium (Keq< 1).d) the products will be favored at equilibrium (Keq> 1).

e) this reaction is completely at equilibrium (Keq= 1).

14.(5 pts) This problem is about the IUPAC (International Union of Pure and Applied Chemistry)

nomenclature of organic compounds. Select the best name for the following molecule 11. (ignore the

relative stereochemistry.)

11

a) (4-Cyclopropyl-3-ethyl-5-methyl)octane

b) (3-Ethyl-5-methyl-4-octyl)cyclopropane

c) (6-Ethyl-5-cyclopropyl-4-methyl)octane

d) (5-Cyclopropyl-6-ethyl-4-methyl)octane

e) (6-Ethyl-4-methyl-5-octyl)cyclopropane

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