MULTIPLE CHOICE QUESTIONS (5 MARKS)
1) Which of the following functional groups will increase the nucleophilicity of an amine
through an inductive effect?
a) Nitro (-NO₂)
b) Methyl (-CH₃)
c) Hydroxyl (-OH)
d) Carboxyl (-COOH)
2) Which of the following has the highest basicity in aqueous solution?
a) Pyridine
b) Aniline
c) p-Nitroaniline
d) p-Methoxyaniline
3) Which of the following best explains why fluoroacetic acid (CH₂FCOOH) is more acidic than
acetic acid (CH₃COOH)?
a) The +I effect of fluorine
b) The -M effect of fluorine
c) The -I effect of fluorine
d) The +M effect of fluorine
4) In 1H-benzo[d]imidazole, which nitrogen is more basic and why?
a) N1, due to its involvement in resonance stabilization of the aromatic ring.
b) N3, because its lone pair is not delocalized and more available for protonation.
c) Both N1 and N3 have equal basicity due to aromatic delocalization.
d) Neither N1 nor N3 is basic due to their sp² hybridization.
5) Based on Hückel's Rule, how would you classify [12]annulene and [10]annulene with respect
to their aromaticity?
a) [12]annulene is aromatic, and [10]annulene is anti-aromatic.
b) [12]annulene is non-aromatic, and [10]annulene is aromatic.
c) [12]annulene is non-aromatic, and [10]annulene is anti-aromatic.
d) [12]annulene is aromatic, and [10]annulene is non-aromatic.
6) Which of the following compounds—ortho-aminobenzonitrile, meta-aminobenzonitrile, or
para-aminobenzonitrile—is the most basic, and what is the primary reason for its basicity?
a) Ortho-aminobenzonitrile (2-aminobenzonitrile), due to the electron-donating effect of the
amino group.
b) Meta-aminobenzonitrile (3-aminobenzonitrile), due to weaker electron-withdrawing inductive
effects from the nitrile group.
c) Para-aminobenzonitrile (4-aminobenzonitrile), due to the electron-donating mesomeric effect
of the amino group and minimal interference from the nitrile group.
d) Benzonitrile, due to the absence of any electron-withdrawing or donating groups
7) Which of the following statements is true about geometrical isomers?
a) Trans isomers are generally more stable than cis isomers due to less steric hindrance.
b) Cis isomers are always more stable than trans isomers.
c) Geometrical isomers cannot be separated because they interconvert rapidly.
d) Geometrical isomerism occurs in single bonds due to restricted rotation.
8) Which of the following best describes the phenomenon of hyperconjugation in organic
molecules?
a) The interaction of sigma bonds with the vacant p-orbitals or pi bonds of adjacent atoms,
leading to delocalization of electrons and stabilization of the molecule.
b) The resonance interaction between lone pairs and pi bonds in a molecule, causing increased
resonance stabilization.
c) The ability of molecules to rotate around single bonds, creating a more stable structure.
d) The interaction between non-bonding electron pairs and antibonding orbitals of neighboring
atoms.
9) Which of the following is not a possible structural isomer for C₃H₆O?
a) Propanal (CH₃CH₂CHO)
b) Acetone (CH₃COCH₃)
c) Propanol (CH₃CH₂CH₂OH)
d) Methoxyethene (CH₃OCH=CH₂)
10) How many structural isomers (constitutional isomers) are possible for the molecular
formula C₃H₆O, considering different functional groups such as aldehydes, ketones, and
alcohols?
a) 3
b) 4
c) 5
d) 6
SHORT QUESTIONS ( 5 MARKS)
Q 1) In the context of the Hammett equation for a series of reactions, what does a positive and
large ρ (rho) value suggest about the nature of the transition state or intermediate?
Q 2) What are the different types of tautomers, and explain the tautomerism observed in 1-(4-
nitrophenyl)-2-phenylpropan-1-one using structures?
Q 3) Identify whether keto, aldehyde, or ester functional groups exhibit the highest percentage of
the enol form, and provide a brief explanation for why this occurs.
Q 4) What is Hückel's Rule, and based on this rule, categorize the following compounds as
aromatic, anti-aromatic, or non-aromatic. (2 MARKS)
Q 5) Identify whether keto, aldehyde, or ester functional groups exhibit the highest percentage of
the enol form, and provide a brief explanation for why this occurs.
LONG QUESTIONS ( 5 MARKS)
Q 1) Suggest IUPAC name of following compounds (0.5 MARKS EACH)
Q 2) Suggest IUPAC name of following compounds (1 MARKS EACH)
