Question 1

Which of the following alkyl halides gives the slowest S_N2 reaction?

Accepted Answer

The slowest reaction will be the one with the most hindered substrate. Choice C has a tert-butyl group, which is the most bulky of the alkyl groups present in the options given. This will make it the slowest to undergo the S_N2 reaction.

Question 2

Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above S_N2 reaction?

Accepted Answer

In an SN1 reaction, the rate is only dependent on the concentration of the carbocation intermediate. Doubling the concentration of the alkyl halide will increase the formation rate of the carbocation, which will result in an increase in the overall reaction rate. Therefore, doubling the concentration of the alkyl halide will double the rate of the reaction.

Question 3

Which of the following S_N2 reactions is the slowest?

Accepted Answer

In reaction B, only one molecule of reactant is required for the reaction to occur, while in all other reactions, two molecules of reactants are required. This means that reaction B has the lowest rate since it has the least number of collisions between reactant molecules. The rate of a reaction is directly proportional to the number of collisions between reactant molecules. Therefore, the slowest reaction is reaction B.

Question 4

Which of the following is a secondary alkyl halide?

Accepted Answer

A secondary alkyl halide is one in which the halogen is attached to a carbon that is bonded to two other carbons. In this case, option C has a bromine atom attached to a carbon atom that is bonded to two other carbon atoms, making it a secondary alkyl halide. The other options either have a primary alkyl halide or a tertiary alkyl halide.

Question 5

Give the mechanism including the transition state.

Accepted Answer

The answer of Give the mechanism including the transition state....

Question 6

Assuming no other changes, what is the effect of doubling both the alkyl halide and the nucleophile concentrations in the above reaction?

Accepted Answer

Doubling both the alkyl halide and the nucleophile concentrations in a reaction typically suggests a second-order reaction (first order with respect to each reactant), so the rate would quadruple because the rate law would be rate = k[alkyl halide][nucleophile]. Doubling each concentration results in 2^2 = 4 times the original rate.

Question 7

Identify the alkyl halide that reacts the fastest in a S_N2 reaction.

Accepted Answer

The answer of Identify the alkyl halide that reacts the...

Question 8

Which of the following are the substitution products of the reaction shown below? CH₃CH₂Br + ^-OH → ?

Accepted Answer

The reactants are a bromoalkane and a hydroxide ion. The hydroxide ion will act as a nucleophile and attack the carbon attached to the bromine, displacing the bromine and forming an alcohol as the product. Therefore, the substitution product will be the bromoalkane with an alcohol group instead of the bromine. Choice C is the only option that shows this product. Choices A, D, and E show additional products that are not formed in this reaction. Choice B is incorrect because it does not show the substitution product, but rather a molecule with an additional hydroxyl group attached to the same carbon as the bromine.

Question 9

Which of the following best describes the carbon-chlorine bond of an alkyl chloride?

Accepted Answer

The carbon-chlorine bond in alkyl halides (chlorides in this case) is polar covalent, with δ+ at carbon and δ- at chlorine. This polarity arises due to the difference in electronegativity between the two atoms. However, the molecule as a whole may not be polar depending on the other atoms or groups attached to the carbon atom.

Question 10

Give the mechanism including the transition state.

Accepted Answer

The answer of Give the mechanism including the transition state....

Question 11

Which of the following is not normally considered to be a nucleophile?

Accepted Answer

The answer of Which of the following is not normally...

Question 12

Identify the strongest nucleophile in an S_N2 reaction.

Accepted Answer

In polar aprotic solvents, nucleophilicity parallels basicity because the solvent does not solvate anions strongly, allowing the inherent nucleophilicity of the anion to dominate. Among the options, the ethoxide ion is the most basic and thus the strongest nucleophile in such a solvent.

Question 13

Which of the following S_N2 reactions is the fastest?

Accepted Answer

The answer of Which of the following S_N2 reactions is...

Question 14

Which of the following S_N2 reactions is the fastest?

Accepted Answer

In this reaction, a nucleophilic substitution is taking place where an iodine atom is being replaced by a hydroxyl group. The reaction rate is dependent on the concentration of the reactants, the strength of the nucleophile and the leaving group. In option B, the nucleophile (HO-) is a strong base and the leaving group (I-) is a weak base. This means that I- can easily leave and be replaced by HO-. Therefore, the reaction will occur at a faster rate compared to other options.

Question 15

Identify the alkyl halide that reacts the fastest in an S_N2 reaction.

Accepted Answer

The reactivity of alkyl halides in S_N2 reaction follows the order: tertiary > secondary > primary. This is because the rate-determining step in this reaction is the formation of the carbocation intermediate, and tertiary carbocations are more stable than secondary and primary carbocations. Among the given options, only 1-iodopropane is a tertiary alkyl halide, and hence it would react the fastest in the S_N2 reaction.

Question 16

Which of the following is not a nucleophile?

Accepted Answer

The answer of Which of the following is not a...

Question 17

Which of the following does not provide evidence that there are two different mechanisms for nucleophilic substitution?

Accepted Answer

The answer of Which of the following does not provide...

Question 18

Which of the following S_N2 reactions is the slowest?

Accepted Answer

The answer of Which of the following S_N2 reactions is...

Question 19

What is the nucleophile in the reaction shown below?

Accepted Answer

The answer of What is the nucleophile in the reaction...

Question 20

Which of the following compounds will undergo an S_N2 reaction most readily?

Accepted Answer

E) is the correct choice because it contains an iodine atom, which is a good leaving group due to its size and bond strength, making it most susceptible to nucleophilic substitution reactions among the options provided.

Quiz 9: Substitution Reactions of Alkyl Halides

Which of the following alkyl halides gives the slowest SN2 reaction?

Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above SN2 reaction?

Which of the following SN2 reactions is the slowest?

Which of the following is a secondary alkyl halide?

Give the mechanism including the transition state.

Assuming no other changes, what is the effect of doubling both the alkyl halide and the nucleophile concentrations in the above reaction?

Identify the alkyl halide that reacts the fastest in a SN2 reaction.

Which of the following are the substitution products of the reaction shown below? CH3CH2Br + -OH → ?

Which of the following best describes the carbon-chlorine bond of an alkyl chloride?

Give the mechanism including the transition state.

Which of the following is not normally considered to be a nucleophile?

Identify the strongest nucleophile in an SN2 reaction.

Which of the following SN2 reactions is the fastest?

Which of the following SN2 reactions is the fastest?

Identify the alkyl halide that reacts the fastest in an SN2 reaction.

Which of the following is not a nucleophile?

Which of the following does not provide evidence that there are two different mechanisms for nucleophilic substitution?

Which of the following SN2 reactions is the slowest?

What is the nucleophile in the reaction shown below?

Which of the following compounds will undergo an SN2 reaction most readily?

Which of the following alkyl halides gives the slowest S_N2 reaction?

Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above S_N2 reaction?

Which of the following S_N2 reactions is the slowest?

Identify the alkyl halide that reacts the fastest in a S_N2 reaction.

Which of the following are the substitution products of the reaction shown below? CH₃CH₂Br + ^-OH → ?

Identify the strongest nucleophile in an S_N2 reaction.

Which of the following S_N2 reactions is the fastest?

Which of the following S_N2 reactions is the fastest?

Identify the alkyl halide that reacts the fastest in an S_N2 reaction.

Which of the following S_N2 reactions is the slowest?

Which of the following compounds will undergo an S_N2 reaction most readily?