Deck 7: Alkenes and Alkynes

Question 1

For a compound containing substituents other than hydrogen, the number of hydrogen atoms in the equivalent hydrocarbon formula is determined by _____ from the number of hydrogen atoms present.

A) subtracting the number of halogens atoms
B) adding two hydrogen atoms for each oxygen
C) subtracting the number nitrogen atoms
D) adding the number of oxygen atoms

Answer 1

adding the number of oxygen atoms

Question 2

Choose substituents X and Y (listed in order below) for the following compound so as to make a Z isomer.

A) −Br, −NHCH₃
B) −F, −CHO
C) −I, −OCH₃
D) −COOH, −CH₂NH₂
E) −Br, −COOH

Answer 2

−F, −CHO

Question 3

A molecule has three degrees of unsaturation. In this molecule there would be

A) three rings
B) three double bonds
C) two rings and one double bond
D) one ring and two double bonds
E) any of these

Answer 3

any of these

Question 4

Dieldrin, C₁₂H₈Cl₆O, is a pentacyclic (five-ring) compound formerly used as an insecticide. Use this information to answer the following question(s).
Refer to instructions. How many double bonds does dieldrin have?

Question 5

Calculate the degree of unsaturation in the formula below. Show your calculations.
caffeine, C₈H₁₀N₄O₂

Question 6

Provide names for each structure below. Be sure to include the cis,trans or E,Z designations where applicable.
Rank each set of substituents using the Cahn-Ingold-Prelog sequence rules by numbering the highest priority substituent 1 and numbering the lowest priority substituent 4. Place the number in the blank below the substituent.

Question 7

Draw structures corresponding to each name below.
Draw:
(3E)-3,7-dimethylocta-1,3,6-triene

Question 8

A compound with the following molecular formula contains two double bonds. What is the correct subscript for H in the formula? C₁₀H_?ClN₂O

A) 19
B) 22
C) 18
D) 20
E) 21

Question 9

Provide names for each structure below. Be sure to include the cis,trans or E,Z designations where applicable.
Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system?

A) −COOH
B) −CHO
C) −CH₂OH
D) −CH₃

Question 10

Pent-2-ene is an example of a disubstituted alkene. Use this alkene to answer the following question(s).
Refer to instructions. Draw the cis and trans isomers of pent-2-ene and label them.

Question 11

What is the IUPAC name of the following compound?

A) (E)-3-methylpent-3-ene
B) (Z)-3-methylpent-3-ene
C) (E)-3-methylpent-2-ene
D) (Z)-3-methylpent-2-ene

Question 12

The following group is a substituent on a molecule. What is an accepted IUPAC name for this group?

A) propenyl
B) allyl
C) vinyl
D) propylene
E) either a or b

Question 13

Provide names for each structure below. Be sure to include the cis,trans or E,Z designations where applicable.
Name and designate:

Question 14

Draw structures corresponding to each name below.
Draw:
trans-4,4-dimethylpent-2-ene

Question 15

Provide names for each structure below. Be sure to include the cis,trans or E,Z designations where applicable.
Name and designate:

Question 16

Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system?

A) −NH₂
B) −NHCH₃
C) −CH₂NH₂
D) −CH₂NHCH₃

Question 17

Provide names for each structure below. Be sure to include the cis,trans or E,Z designations where applicable.
Name and designate:

Question 18

Name this compound.

Question 19

Dieldrin, C₁₂H₈Cl₆O, is a pentacyclic (five-ring) compound formerly used as an insecticide. Use this information to answer the following question(s).
Refer to instructions. Calculate the degree of unsaturation for Dieldrin.

Question 20

Pent-2-ene is an example of a disubstituted alkene. Use this alkene to answer the following question(s).
Refer to instructions. Circle the isomer of pent-2-ene that is most stable.

Question 21

The following reaction is carried out in cyclohexane with the application of heat. Write the complete equation for the reaction below. If more than one major organic product is expected, draw each one.

Question 22

Alkene chemistry is dominated by what type of reaction?

A) substitution
B) electrophilic addition
C) nucleophilic addition
D) elimination
E) both b and c

Question 23

Assign E or Z configurations to each alkene below.
Assign:

Question 24

Match each definition to the term it describes.
Predicts that the transition state of an exergonic reaction step structurally resembles the reactant.

A)Hammond Postulate
B)Cahn-Ingold-Prelog Rules
C)Markovnikov's Rule
D)Degrees of Unsaturation

Question 25

Hydride shifts

A) occur to form less highly substituted carbocations.
B) occur by transfer of an H⁺ between adjacent carbon atoms.
C) are observed only in single step reactions.
D) transfer positive charge to a more highly substituted carbon atom.

Question 26

Match each definition to the term it describes.
Predicts that the more stable carbocation intermediate is formed in electrophilic additions to alkenes.

A)Hammond Postulate
B)Cahn-Ingold-Prelog Rules
C)Markovnikov's Rule
D)Degrees of Unsaturation

Question 27

Assign E or Z configurations to each alkene below.
Assign:

Question 28

Which of the following would have the smallest ΔH°_hydrog?

A)

B)

C)

D)

Question 29

Using curved arrows, write a mechanism for the following reaction. If carbocations are formed, specify if they are primary, secondary or tertiary.

Question 30

What alkene would you use to prepare the following alkyl halide?

Question 31

Rank the carbocations below in order of increasing stability (least stable = 1; most stable = 3). Place the number corresponding to the carbocation's relative stability in the blank below the structure.

Question 32

Match each definition to the term it describes.
Predicts the total number of multiple bonds and rings.

A)Hammond Postulate
B)Cahn-Ingold-Prelog Rules
C)Markovnikov's Rule
D)Degrees of Unsaturation

Question 33

Below are all the chemical structures and intermediates involved in a reaction. On the structures provided, show all electron flow using the arrow formalism for the complete stepwise mechanism.

Question 34

Predict the major organic product(s) in the reaction below. If more than one major organic product is expected, draw each one.

Question 35

Below are all the chemical structures and intermediates involved in a reaction. Why does the rearrangement that results in the formation of product B occur?

Question 36

Predict the major organic product(s) in the reaction below. If more than one major organic product is expected, draw each one. Explain the significance of "35°C" and "ether" shown in the reaction.