New York University

BIOCHEMIST 406

1)Which of the following is the correct molecular formula for nonane?

1. 1. C₇H₁₆
   2. C₉H₂₀
   3. C₁₁H₂₄
   4. none of these

2. Of the hydrocarbons given here, which contains the most carbon atoms?
   1. butane
   2. pentane
   3. ethane
   4. propane

3. Dodecane is a 12 carbon alkane. How many hydrogen atoms are in dodecane?
   1. 12
   2. 24
   3. 26
   4. 28

4. Eicosane is a 20 carbon alkane. How many hydrogen atoms are in eicosane?
   1. 38
   2. 40
   3. 42
   4. 44

5. Which of the following represents the molecular formula for an unbranched alkane?
   1. C₅H₁₀
   2. C₆H₁₀
   3. C₇H₁₈
   4. C₈H₁₈

6. Which of the following is not the molecular formula of a non-cyclic alkane?
   1. C₁₅H₃₂
   2. C₁₉H₃₈
   3. C₂₀H₄₂
   4. C₂₂H₄₆

7. Which of the following represents the molecular formula for a non-cyclic alkane?
   1. C₁₅H₃₀
   2. C₁₉H₄₀
   3. C₂₀H₄₀
   4. all of them

8. Which of the following is not the molecular formula of an alkane?
   1. C₁₅H₃₂
   2. C₁₉H₄₀
   3. C₂₀H₄₂
   4. none of them, these are all alkanes

9. Which of the following correctly describes the relationship between butane and 2-methylpropane?
   1. they have the same molecular formula
   2. they have the same chemical properties
   3. they have the same physical properties
   4. all of the above are true

10. What is the molecular formula for the following compound:   ?
    1. C₇H₁₆
    2. C₈H₁₆
    3. C₈H₁₇
    4. C₈H₁₈

11. Which of the following compounds are constitutional isomers?

(i)    (ii)                                  (iii)

1. 1. (i) and (ii)
   2. (i) and (iii)
   3. (ii) and (iii)
   4. all of them

12. The formula of a particular compound can be written as

1. C₄H₁₀
2. CH₃CH₂CH₂CH₃
3. CH₃(CH₂)₂CH₃

13. Which of the following is true?

1. all of these provide exactly the same amount of information
2. formula (ii) provides more information than formulas (i) or (iii)
3. formulas (ii) and (iii) provide exactly the same amount of information
4. no two of these provide exactly the same amount of information

14. Which of the following are representations of the same molecule?

(i)                 CH₃CH₂CH₂CH₂CH₂CH₂ (ii)

(iii)

1. only (i) and (ii)
2. only (i) and (iii)
3. only (ii) and (iii)
4. all of them

15. Which of the following are representations of the same molecule?

(i)                 CH₃CH₂CH₂CH₂CH₂CH₂CH₃ (ii)

(iii)

1. only (i) and (ii)
2. only (i) and (iii)
3. only (ii) and (iii)
4. none of them

16. Which of the following are representations of the same molecule?

(i)                 CH₃CH₂CH₂CH₂CH₂CH₂CH₃ (ii)

(iii)

1. only (i) and (ii)
2. only (i) and (iii)
3. only (ii) and (iii)
4. none of them

17. Which of the following are representations of the same molecule?

(i)                 CH₃CH₂CH₂CH₂CH₂CH₂CH₃ (ii)

(iii)

1. only (i) and (ii)
2. only (i) and (iii)
3. only (ii) and (iii)
4. none of them

18. Which of the following is a constitutional isomer of butane, CH₃(CH₂)₂CH₃?

A.

B.

C.

D. all of these

19. Which of the following is(are) constitutional isomer(s) of hexane, CH₃(CH₂)₄CH₃?

A.

B.

C. both (a) and (b)

D. neither (a) nor (b)

20. Which of the following is(are) constitutional isomer(s) of hexane, CH₂(CH₂)₄CH₃?

A.

B.

C. both (a) and (b)

D. neither (a) nor (b)

21. How many constitutional isomers are there with the formula C₆H₁₄?
    1. 4
    2. 5
    3. 6
    4. 7

22. When naming a branching substituent in an alkane, which of the following is the correct procedure?
    1. add the suffix -yl to the name of the parent hydrocarbon
    2. replace the suffix -ane with the suffix -yl
    3. replace the suffix -ane with the suffix -anyl
    4. insert -yl before the suffix –ane

23. Which of the following is true of branched chain hydrocarbons?
    1. the longest carbon chain becomes the root name
    2. the longest carbon chain is always written horizontally
    3. both (a) and (b)
    4. neither (a) nor (b)