CHM 231 Exam One

 

For each question, indicate the best answer of those available on the scanner form. Turn in only the scanner form; you may take the actual exam with you. The last page of the exam is a periodic chart. 25 questions; equal weighting.

 

1. The F-B-F bond angle in the neutral molecule BF3 is closest to:

 

a.                   90 degrees

b.                  109.5 degrees

c.                   120 degrees

d.                  180 degrees

 

2. The relationship of the following two structures is:

 

 

a.                   positional isomers

b.                  geometric isomers

c.                   skeletal isomers

d.                  two views of the same molecule

 

3. The formal charge on carbon in the following Lewis structure is:

 

 

a.                   zero

b.                  1

c.                   2

d.                  +1

e.                   +2

 

 

 

 

 

4. How many units of unsaturation in a compound with the formula C4H10O2?

 

a.                   zero

b.                  one

c.                   two

d.                  three

e.                   four

 

5. Which phrase best describes the most stable conformation of methyl cyclohexane?

 

a.                   boat

b.                  flat

c.                   chair, with an axial methyl group

d.                  chair, with an equatorial methyl group

 

For questions six and seven, consider the following Lewis structure?

 

 

6. What is the hybridization of the sulfur?

 

a.                   p

b.                  sp

c.                   sp2

d.                  sp3

 

7. What is the formal charge of the oxygen?

 

a.                   zero

b.                  +1

c.                   +2

d.                  1

e.                   2

 

 

 

 

 

 

 

8. The IUPAC name of the following structure is:

 

 

a.                   Z-3-isopropyl-2-hexene

b.                  E-3-isopropyl-2-hexene

c.                   Z-4-methyl-3-propyl-2-pentene

d.                  E-4-methyl-3-propyl-2-pentene

 

9. Which Newman projection represents 1,2-dichloroethane in the anti conformation?

 

 

10. Which compound is incapable of having a geometric isomer?

 

a.                   1,1-dimethylcyclohexane

b.                  1,2-dimethylcyclohexane

c.                   1,3-dimethylcyclohexane

d.                  1,4-dimethylcyclohexane

 

 

For questions eleven through thirteen, consider the following Lewis structure:

 

 

 

11. What is the overall charge of the structure shown?

 

a.                   zero

b.                  +1

c.                   +2

d.                  1

e.                   2

 

12. What is the formal charge of the central nitrogen?

 

a.                   zero

b.                  +1

c.                   +2

d.                  1

e.                   2

 

13. What is the N-N-N bond angle?

 

a.                   90 degrees

b.                  109.5 degrees

c.                   120 degrees

d.                  180 degrees

 

14. What is the IUPAC name of the following compound?

 

 

 

a.                   5-ethylhexane

b.                  2-ethylhexane

c.                   3-methylheptane

d.                  5-methylheptane

 

 

 

 

 

 

 

 

 

 

 

15. How many units of unsaturation are in the following structure?

 

 

 

a.                   zero

b.                  one

c.                   two

d.                  three

e.                   four

 

16. The hybridization of carbon in the following structure is:

 

 

 

a.                   p

b.                  sp

c.                   sp2

d.                  sp3

 

17. The number of valence electrons in about a boron atom is:

 

a.                   three

b.                  four

c.                   five

d.                  six

e.                   seven

 

18. The name 2-isopropyl-2-propene is incorrect. The corrected IUPAC name should be:

 

a.                   2,3-dimethyl-1-butene

b.                  2,3-dimethyl-2-butene

c.                   2-methyl-iso-pentene

d.                  2-methyl-1-isopentene

 

19. The IUPAC name for the following structure is:

 

 

a.                   2,3-dimethylcyclohexene

b.                  1,6-dimethylcyclohexene

c.                   1,2-dimethyl-2-cyclohexene

d.                  1,2-dimethylcyclohexene

 

 

20. What is the relationship between the following two structures?

 

 

 

a.                   conformers

b.                  geometric isomers

c.                   positional isomers

d.                  identical structures

 

21. The structure of cis-1,3-dichlorocyclohexane in its most stable conformation is:

 

 

 

 

22. The IUPAC name of the following compound is:

 

 

a.                   E-4-bromo-3-pentene

b.                  Z-4-bromo-3-pentene

c.                   Z-2-bromo-2-pentene

d.                  E-2-bromo-2-pentene

 

 

23. The units of unsaturation in a formula of C4H6N2OCl2 is:

 

a.                   one

b.                  two

c.                   three

d.                  four

 

24. Which compound could be said to have a Z configuration?

 

 

 

 

 

 

 

 

 

 

 

 

 

25. The IUPAC name for the following structure is:

 

 

 

a.                   2-methyl-8,8-dichloro-4-octyne

b.                  1,1-dichloro-7-methyl-4-octyne

c.                   E-1,1-dichloro-7-methyl-4-octyne

d.                  Z-1,1-dichloro-7-methyl-4-octyne