Question 1

An alkene adds hydrogen in the presence of a catalyst to give 3,4-dimethylhexane.Ozonolysis of the alkene followed by treatment with zinc and acetic acid gives a single organic product.The structure of the alkene is:

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Question 2

An alkene with the molecular formula C₈H₁₆undergoes ozonolysis to yield a mixture of (CH₃)₂C=O and (CH₃)₃CCHO.The alkene is:

Accepted Answer

The ozonolysis products indicate that the alkene must have a structure that can be split into (CH₃)₂C=O and (CH₃)₃CCHO. 2,4,4-Trimethyl-2-pentene fits this requirement.

Question 3

Select the structure of the major product formed in the following reaction.

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Question 4

What is the major product of the following reaction sequence?

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Question 5

Addition of 2 mol of HCl to 1-butyne would yield:

Accepted Answer

The addition of 2 mol of HCl to 1-butyne would yield a product with a saturated carbon chain and two chloride atoms. The correct product would be CH3CH2CH(Cl)CH2Cl, which is represented by option B. Option A, C, and E have incorrect structures with missing or extra atoms. Option D has a double bond, which contradicts the product of the addition reaction.

Question 6

Compound C has the molecular formula C₇H_12.On catalytic hydrogenation,1 mol of C absorbs 1 mol of hydrogen and yields a compound with the molecular formula C₇H₁₄.On ozonolysis and subsequent treatment with zinc and acetic acid,C yields only: The structure of C is:

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Question 7

Which of the following could be used to distinguish between 1-octyne and 3-octyne?

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Question 8

An unknown compound,A,has the molecular formula C₇H₁₂.On oxidation with hot aqueous potassium permanganate,A yields CH₃CH₂COOH and (CH₃)₂CHCOOH.Which of the following structures best represents A?

Accepted Answer

The answer of An unknown compound,A,has the molecular formula C₇H₁₂.On...

Question 9

What is the major product of the following reaction sequence?

Accepted Answer

The first step of the reaction sequence converts the starting material into an alkene through elimination of water. The alkene is then subjected to hydrogenation, which adds two hydrogen atoms across the double bond. The only product that results from these reactions is the compound shown in choice A.

Question 10

One mole of an optically active compound,X,with the molecular formula C₆H₈ reacts with three moles of hydrogen in the presence of a catalyst to yield an optically inactive product that cannot be resolved.X also exhibits IR absorption at approximately 3300 cm^-1.Which is a possible structure for X?

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Question 11

What compound would yield an equimolar mixture of CH₃CH₂CH₂CHO and CH₃CHO upon treatment with O₃,followed by Zn/HOAc?

Accepted Answer

Ozonolysis of 1-hexene and cis-2-hexene will yield an equimolar mixture of CH3CH2CH2CHO and CH3CHO. Trans-2-hexene will yield only CH3CH2CH2CHO.

Question 12

Which reagent or test could be used to distinguish between 3-pentyne and 1-pentyne?

Accepted Answer

IR spectroscopy can differentiate between 3-pentyne and 1-pentyne based on their unique vibrational frequencies. The C≡C stretch for 3-pentyne occurs at around 2260-2280 cm^-1, while the C≡C stretch for 1-pentyne occurs at around 2210-2230 cm^-1. The other reagents and tests listed do not specifically differentiate between these two isomers.

Question 13

Addition of excess HCl to 2-methyl-3-heptyne would produce: 2-methyl-3,3-dichloroheptane 2-methyl-2,3-dichloroheptane
I II
2-methyl-4,4-dichloroheptane 2-methyl-3,4-dichloroheptane
III IV
2-methyl-3-chloroheptene
V

Accepted Answer

The addition of excess HCl to 2-methyl-3-heptyne would result in the formation of a chlorinated compound. The major product would be 2-methyl-2,3-dichloroheptane (option II), as the secondary carbocation intermediate formed during the reaction would lead to this product via rearrangement. Option I (2-methyl-3,3-dichloroheptane) would be a minor product formed via direct addition without rearrangement. Option III (2-methyl-4,4-dichloroheptane) and IV (2-methyl-3,4-dichloroheptane) are not formed as they would require unlikely rearrangement pathways. Option V (2-methyl-3-chloroheptene) is not formed as excess HCl would lead to complete chlorination rather than partial chlorination and formation of an alkene.

Question 14

What is the major product of the following reaction sequence?

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Question 15

The conversion of ethylene to vinyl bromide can be accomplished by use of these reagents in the order indicated.

Accepted Answer

The conversion of ethylene to vinyl bromide involves adding a bromine atom to one of the double bond carbons in ethylene. This is commonly done through a halogenation reaction, where a halogen (in this case, bromine) is added to the alkene in the presence of a catalyst. This is the first step in choice B, where Br2 is added to ethylene to form 1,2-dibromoethane. The second step in choice B involves using sodium ethoxide (NaOCH2CH3) to deprotonate the alpha-carbon in 1,2-dibromoethane, creating a carbanion that can be attacked by a bromide ion to form vinyl bromide. Therefore, choice B is the best option.

Question 16

Select the structure of the major product formed in the following reaction.

Accepted Answer

The reaction involves a Grignard reaction with an ester. The Grignard reagent attacks the carbonyl carbon of the ester, forming a tetrahedral intermediate. The intermediate collapses to form a ketone, which is the major product. Since both R-groups on the ketone are the same (methyl), the product is symmetrical. The only symmetrical option among the choices is III.

Question 17

A reagent or test that could be used to distinguish between 1-pentene and 1-pentyne would be:

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Question 18

What is the major product for the following reaction?

Accepted Answer

The reaction is a Friedel-Crafts acylation of benzene with acetyl chloride in the presence of aluminum chloride. The major product will be the monoacetylated benzene derivative, which is formed by the substitution of one hydrogen atom in benzene with an acetyl group (-COCH3). Choice C shows the correct structure of the product.

Question 19

Which of the following could be used as the basis for a simple test that would distinguish between 1-pentyne and pentane?

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Question 20

What is the major product of the following reaction sequence?

Accepted Answer

The reaction sequence starts with the condensation of ethyl acetoacetate (1) with benzaldehyde (2) catalyzed by piperidine to give chalcone (3). Chalcone (3) undergoes intramolecular Michael addition in the presence of KOH to form coumarin (4). The major product of this reaction sequence is coumarin with the given structure in choice C.

Quiz 8: Alkenes and Alkynes Ii: Addition Reactions

An alkene adds hydrogen in the presence of a catalyst to give 3,4-dimethylhexane.Ozonolysis of the alkene followed by treatment with zinc and acetic acid gives a single organic product.The structure of the alkene is:

An alkene with the molecular formula C₈H₁₆undergoes ozonolysis to yield a mixture of (CH₃) ₂C=O and (CH₃) ₃CCHO.The alkene is:

Select the structure of the major product formed in the following reaction.

What is the major product of the following reaction sequence?

Addition of 2 mol of HCl to 1-butyne would yield:

Compound C has the molecular formula C₇H_12.On catalytic hydrogenation,1 mol of C absorbs 1 mol of hydrogen and yields a compound with the molecular formula C₇H₁₄.On ozonolysis and subsequent treatment with zinc and acetic acid,C yields only: The structure of C is:

Which of the following could be used to distinguish between 1-octyne and 3-octyne?

An unknown compound,A,has the molecular formula C₇H₁₂.On oxidation with hot aqueous potassium permanganate,A yields CH₃CH₂COOH and (CH₃) ₂CHCOOH.Which of the following structures best represents A?

What is the major product of the following reaction sequence?

What compound would yield an equimolar mixture of CH₃CH₂CH₂CHO and CH₃CHO upon treatment with O₃,followed by Zn/HOAc?

Which reagent or test could be used to distinguish between 3-pentyne and 1-pentyne?

Addition of excess HCl to 2-methyl-3-heptyne would produce: 2-methyl-3,3-dichloroheptane 2-methyl-2,3-dichloroheptane I II 2-methyl-4,4-dichloroheptane 2-methyl-3,4-dichloroheptane III IV 2-methyl-3-chloroheptene V

What is the major product of the following reaction sequence?

The conversion of ethylene to vinyl bromide can be accomplished by use of these reagents in the order indicated.

Select the structure of the major product formed in the following reaction.

A reagent or test that could be used to distinguish between 1-pentene and 1-pentyne would be:

What is the major product for the following reaction?

Which of the following could be used as the basis for a simple test that would distinguish between 1-pentyne and pentane?

What is the major product of the following reaction sequence?

Quiz 8: Alkenes and Alkynes Ii: Addition Reactions

An alkene adds hydrogen in the presence of a catalyst to give 3,4-dimethylhexane.Ozonolysis of the alkene followed by treatment with zinc and acetic acid gives a single organic product.The structure of the alkene is:

An alkene with the molecular formula C8H16 undergoes ozonolysis to yield a mixture of (CH3) 2C=O and (CH3) 3CCHO.The alkene is:

Select the structure of the major product formed in the following reaction.

What is the major product of the following reaction sequence?

Addition of 2 mol of HCl to 1-butyne would yield:

Compound C has the molecular formula C7H12.On catalytic hydrogenation,1 mol of C absorbs 1 mol of hydrogen and yields a compound with the molecular formula C7H14.On ozonolysis and subsequent treatment with zinc and acetic acid,C yields only: The structure of C is:

Which of the following could be used to distinguish between 1-octyne and 3-octyne?

An unknown compound,A,has the molecular formula C7H12.On oxidation with hot aqueous potassium permanganate,A yields CH3CH2COOH and (CH3) 2CHCOOH.Which of the following structures best represents A?

What is the major product of the following reaction sequence?

One mole of an optically active compound,X,with the molecular formula C6H8 reacts with three moles of hydrogen in the presence of a catalyst to yield an optically inactive product that cannot be resolved.X also exhibits IR absorption at approximately 3300 cm-1.Which is a possible structure for X?

What compound would yield an equimolar mixture of CH3CH2CH2CHO and CH3CHO upon treatment with O3,followed by Zn/HOAc?

Which reagent or test could be used to distinguish between 3-pentyne and 1-pentyne?

Addition of excess HCl to 2-methyl-3-heptyne would produce: 2-methyl-3,3-dichloroheptane 2-methyl-2,3-dichloroheptane I II 2-methyl-4,4-dichloroheptane 2-methyl-3,4-dichloroheptane III IV 2-methyl-3-chloroheptene V

What is the major product of the following reaction sequence?

The conversion of ethylene to vinyl bromide can be accomplished by use of these reagents in the order indicated.

Select the structure of the major product formed in the following reaction.

A reagent or test that could be used to distinguish between 1-pentene and 1-pentyne would be:

What is the major product for the following reaction?

Which of the following could be used as the basis for a simple test that would distinguish between 1-pentyne and pentane?

What is the major product of the following reaction sequence?

An alkene with the molecular formula C₈H₁₆undergoes ozonolysis to yield a mixture of (CH₃) ₂C=O and (CH₃) ₃CCHO.The alkene is:

Compound C has the molecular formula C₇H_12.On catalytic hydrogenation,1 mol of C absorbs 1 mol of hydrogen and yields a compound with the molecular formula C₇H₁₄.On ozonolysis and subsequent treatment with zinc and acetic acid,C yields only: The structure of C is:

An unknown compound,A,has the molecular formula C₇H₁₂.On oxidation with hot aqueous potassium permanganate,A yields CH₃CH₂COOH and (CH₃) ₂CHCOOH.Which of the following structures best represents A?

What compound would yield an equimolar mixture of CH₃CH₂CH₂CHO and CH₃CHO upon treatment with O₃,followed by Zn/HOAc?