chapter 3 school practice questions

Question 1

Identify the functional groups

Answer 1

In the given structure of Darvon (an analgesic), let’s identify the functional groups present:
1. Ester Group (-COO-): Present in the ethyl group (CH₃CH₂CO₂-), connected to the central carbon atom.
2. Benzyl Group (-CH₂-Ph): A benzene ring attached via a CH₂ group.
3. Phenyl Group (Ph): Another benzene ring directly attached to the central carbon atom.
4. Aminomethyl Group (-CH₂N(CH₃)₂): A methylated amine group attached via a CH₂ bridge.

Question 2

Problem 3.18
Label the electrophilic and nucleophilic sites in each molecule:

Answer 2

a) Cyclohexyl bromide (C6H11Br):

Electrophilic site: The carbon atom attached to the bromine.
Reason: The electronegative bromine atom withdraws electron density from the carbon, making it partially positive and susceptible to nucleophilic attack.
Nucleophilic site: The bromine atom.
Reason: Bromine can act as a leaving group, carrying a lone pair of electrons.
b) Water (H2O):

Nucleophilic site: The oxygen atom.
Reason: Oxygen has lone pairs of electrons that can be donated to an electrophile.
c) Benzene (C6H6):

Nucleophilic site: The π-electrons in the aromatic ring.
Reason: The delocalized π-electrons in benzene can be donated to an electrophile during electrophilic aromatic substitution.
d) Cyclohexyl imine (C6H11N=CH3):

Electrophilic site: The carbon atom in the C=N bond.
Reason: The nitrogen atom withdraws electron density from the carbon, making it partially positive.
Nucleophilic site: The nitrogen atom in the C=N bond.
Reason: Nitrogen has a lone pair of electrons that can act as a nucleophile.