Nucleophilic Substitution Reaction

What is the role of a nucleophile in a nucleophilic substitution reaction?

• Nucleophiles prevent the reaction from occurring

• The role of a nucleophile is to stabilize the leaving group

• The role of a nucleophile in a nucleophilic substitution reaction is to attack the electrophilic center of a molecule and displace a leaving group.

• Nucleophiles act as catalysts in the reaction

How does the strength of a nucleophile affect the rate of a nucleophilic substitution reaction?

• A stronger nucleophile leads to a slower nucleophilic substitution reaction.

• The rate of a nucleophilic substitution reaction decreases with the strength of the nucleophile.

• The strength of the nucleophile has no effect on the rate of a nucleophilic substitution reaction.

• The rate of a nucleophilic substitution reaction increases with the strength of the nucleophile.

How does the presence of an electron withdrawing group (-NO2 ) at ortho- and para-positions affect the rate of given reaction?

• paranitrochlorobenzene reacts faster than orthoparadinitrochlorobenzne

• decreases the rate of reaction

• meta position will be speeding up the reaction than ortho para position

• increases the reactivity of haloarenes.

Compare the leaving group ability of iodide ion (I-) and fluoride ion (F-) in a nucleophilic substitution reaction.

• Iodide ion (I-) has lower leaving group ability than fluoride ion (F-).

• Fluoride ion (F-) has similar leaving group ability to iodide ion (I-).

• Fluoride ion (F-) has higher leaving group ability than iodide ion (I-).

• Iodide ion (I-) has higher leaving group ability than fluoride ion (F-).

How does steric hindrance impact the rate of a nucleophilic substitution reaction?

• Steric hindrance has no impact on the rate of a nucleophilic substitution reaction.

• Steric hindrance increases the rate of a nucleophilic substitution reaction.

• Steric hindrance only impacts the rate of an elimination reaction, not a nucleophilic substitution reaction.

• Steric hindrance decreases the rate of a nucleophilic substitution reaction.

Which of the following mechanisms of action occur when there are electron withdrawing groups on the aromatic ring during nucleophilic substitution?

• increases the rate of nucleophilic aromatic substitution.

• decreases the rate of nucleophilic aromatic substitution.

Difference in hybridisation of carbon atom in C—X bond:

In haloalkane, the carbon atom attached to halogen is......................... and in haloarene, the carbon atom attached to halogen is ....................................

• sp2 hybridised,

  sp3 hybridised

• sp3 hybridised, sp2 hybridised,

• sp hybridised, sp2 hybridised,

• sp3 hybridised, sp hybridised,

Discuss the difference between SN1 and SN2 mechanisms in nucleophilic substitution reactions.

• SN1 reactions are bimolecular and proceed through a carbocation intermediate.

• SN1 reactions are bimolecular and proceed through a concerted mechanism.

• SN1 reactions are unimolecular and proceed through a carbocation intermediate, while SN2 reactions are bimolecular and proceed through a concerted mechanism.

• SN2 reactions are unimolecular and proceed through a concerted mechanism.