Ch 334                                   Name _____________________________________

Midterm Exam #1

October 29, 2003

 

 

1.                  (2 pts)  What is the molecular formula of the following molecule?

 

 

 

 

 

 

 

 

 

 


2.                  (4 pts)  Which of the following describes the relationship between the two structures shown below.  Circle the correct response.

 

 

 

 

 

 

 

 

 

 

 


            identical structures   

           

resonance forms      

           

constitutional isomers

 

different compounds with different compositions

 

 

3.                  (3 pts)  Based on the VSEPR theory, which of the following species has (have) a trigonal planar geometry?  Circle them.

 

 

BCl3                            NH3                             NO3-

 

 

4.                  (3 pts)  Which of the following molecules would you expect to have a dipole moment?  Circle them.

 

 

CO2                             HCN                            CHCl3

 

 

5.                  (4 pts)  Diazomethane is an unstable compound which looses a nitrogen molecule when it decomposes.  What species is formed when the nitrogen molecule is lost?  Circle your answer.  (HINT:  draw the Lewis structure for the nitrogen molecule to help figure out this question).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


6.                  (6 pts)  (a)  What is the hybridization of the carbon atom indicated by the arrow in the molecule limonene? Place your answer in the blank provided.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


(b)       There are  ________ sigma bonds and ________ pi bonds in limonene?

 

7.                  (12 pts)  Give the correct IUPAC names for the following compounds.

 

                            CH3      CH3

 

 


(a)       CH3CHCH2CHCH2CH2CHCH3

 

                                                           CH2CH3

 

 

 

 

 

 


            (b)       CH3CH2CH(CH3)C(CH3)3

 

 

 

 

 

 

 


            (c)       

 

 

 

 

 

 

 

 

 

 

 

 

 

 


            (d)

 

 

 

 

 

 

 

 


8.                  (9 pts)  Identify the relationship between the two structures of each pair.   Place the letter of the appropriate response in the blanks provided.

 

A.      identical

B.      different conformations of the same compound

C.      stereoisomers

D.      constitutional isomers

 

 


______  (a) 

 

           

 

 

 

 

 

 

 

 


______  (b)

 

 

 

 

 

 

 

 


______(c)   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9.                  (6 pts)  Use the sawhorse drawing of the following molecule to answer this question.

 

 

 

 

 

 

 

 

 

 

 

(a)               The two bromine atoms in this structure have what relationship?  Circle the correct response.

 

anti                  eclipsed                     gauche                       skewed

 

 

(b)               What is the dihedral (torsion) angle between the two bromine atoms?  Circle the correct response.

 

0o                    30o                  60o                  90o

 

 

10.             (4 pts)  Circle the statement that is correct concerning the relative stabilities of the two conformations, A and B, shown below.

 

 

 

 

 

 

 

 

 


A is more stable

 

B is more stable

 

A and B are equal in stabilities

 

A and B are not equal in stability, but the preferred conformation cannot be determined by inspection

 

 

11.             (4 pts)  What is the spatial relationship of the two bromine atoms in the following structure?  Circle your answer.

 

 

 

 

 

 

 

 

            gauche                       anti                  eclipsed                     skewed

 

12.             (4 pts)  Draw the most stable conformation of trans-1-tert-butyl-3-methylcyclohexane.   All you need to do is add the substituents to the skeleton below.

 

 

 

 

 

 

 

 


13.             (4 pts)  Which constitutional isomer of dimethylcyclohexane does not exhibit cis, trans isomerism?  Circle your answer.

 

1,1-dimethylcyclohexane

 

1,2-dimethylcyclohexane

 

1,3-dimethylcyclohexane

 

1,4-dimethyl cyclohexane

 

 

14.             (4 pts)  Circle the isomer of C5H10 that would be expected to have the highest heat of combustion.

 

methylcyclobutane                                         cyclopentane

 

cis-1,2-dimethylcyclopropane                      trans-1,2-dimethylcyclopropane

 

 

 

 

15.             (4 pts)  Circle the compound that would be expected to have the lowest boiling point.

 

 

 

 

 

 

 

 

 

 


16.             (6 pts)  Which is the stronger base: (Circle it)

 

(CHe)3N:                     (CHe)3P:

 

 

17.             (6 pts)  Indicate whether the carbon-containing compound in each of the following transformations undergoes oxidation, reduction or has no change in oxidation state.