ORGANIC CHEMISTRY| FROM QUESTION TO PERFECTION|
STUDY WITH CONFIDENCE!
Course Code:
Course Title: ORGANIC CHEMISTRY.
Programme:
Academic Year: 2026/2027
Duration: 2 Hours
Total Marks: 100
Candidate Instructions:
1) Write your Registration Number on every answer booklet used.
2) Answer ALL questions in Section A and ANY TWO (2) questions in Section B.
3) Read each question carefully before answering.
4) Begin each question on a new page.
5) The marks for each question are indicated in brackets.
6) This paper consists of several printed pages, including this page.
7) Ensure your copy is complete before the examination begins.
8) Unauthorized materials and communication with other candidates are not permitted.
Turn Over.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,Alkane Answer: a hydrocarbon containing only single covalent bonds
Ketone Answer: An organic compound with a carbonyl group of which the carbon atom is
bonded to two other carbons.
Alkoxy Answer: is an -OR group, an alkyl (or aryl) groupatttached to an oxygen atom.
Carbonyl Answer: carbon atom with a double bond to an oxygen atom
Hydroxyl Answer: A functional group consisting of a hydrogen atom joined to an oxygen atom
by a polar covalent bond. Molecules possessing this group are soluble in water and are called
alcohols.
Acetyl Answer: In organic chemistry, acetyl is a functional group, the acyl with chemical
formula CH3CO. It is sometimes represented by the symbol Ac (not to be confused with the
element actinium). The acetyl group contains a methyl group single-bonded to a carbonyl.
Gem-/Vic- Answer: Vicinal on 2 different adjacent carbons
Geminal- on same carbon
Tosyl Answer: a compound containing the functional group -SO3C6H4CH3, derived from
toluenesulfonic acid.
Mesyl Answer: a compound containing the functional group -SO3CH3, derived from
methanesulfonic acid.
Anhydride Answer: A functional group containing two carbonyls separated by an oxygen atom
(RCOOCOR); often the condensation dimer of a carboxylic acid.
Aryl Answer: organic halide in which the halogen atom is attached to an aromatic ring, such as
a benzene ring
Halogens (fluorine, chlorine, bromine, iodine, astatine) are nonmetal elements that are highly
electronegative and reactive.
Benzyl Answer: benzyl is the substituent or molecular fragment possessing the structure
C6H5CH2-. Benzyl features a benzene ring attached to a CH2 group.
Vinyl Answer: vinyl or ethenyl is the functional group −CH=CH2, namely the ethylene (IUPAC
ethene) molecule (H2C=CH2) minus one hydrogen atom. The name is also used for any
compound containing that group, namely R−CH=CH2 where R is any other group of atoms.
Allyl Answer: An allyl group is a substituent with the structural formula H2C=CH-CH2R,
where R is the rest of the molecule
Nitrile Answer: A nitrile is an organic chemical that contains a cyano functional group
(subunit), CN-, in which the carbon and nitrogen atoms have a triple bond i.e. C≡N-. The
general chemical formula of a nitrile is RCN, where R is the organic group.
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2
,Epoxide Answer: `
Enamine/Imine Answer: An enamine is an unsaturated compound derived by the condensation
of an aldehyde or ketone with a secondary amine. Enamines are considered to be nitrogen
analogs of enols. If one of the nitrogen substituents is a hydrogen atom, H, it is the tautomeric
form of an imine.
Acyl Answer: a functional group derived by the removal of one or more hydroxyl groups from
an oxoacid,[1] including inorganic acids. It contains a double bonded oxygen atom and an alkyl
group.
Aliphatic Answer: In organic chemistry, hydrocarbons (compounds composed of carbon and
hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds also
known as non-aromatic compounds.
Aliphatics can be cyclic, but only aromatic compounds contain an especially stable ring of
atoms, such as benzene.
Aliphatic compounds can be saturated, like Hexane, or unsaturated, like Hexene and Hexyne.
Open-chain compounds (whether straight or branched) contain no rings of any type, and are thus
aliphatic.
Sulphone Answer: an organic compound containing a sulfonyl group linking two organic
groups.
Nitro Answer: Nitro compounds are organic compounds that contain one or more nitro
functional groups (−NO2). The nitro group is one of the most common explosophores
(functional group that makes a compound explosive) used globally. The nitro group is also
strongly electron-withdrawing
Acetal Answer: An acetal is a functional group with the following connectivity R2C(OR')2,
where both R' groups are organic fragments.
Ketal Answer: term ketal is sometimes used to identify structures associated with ketones rather
than aldehydes and, historically, the term acetal was used specifically for the aldehyde cases.
Hemiacetal Answer: A functional group that contains a carbon atom bonded to one -OR group,
one -OH group, an alkyl chain, and a hydrogen atom.
Hemiketal Answer: A carbon atom bonded to two alkyl groups, an -OR group, and an -OH
group
Meth Answer: 1
eth Answer: 2
prop Answer: 3
but- Answer: 4
pent- Answer: 5
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3
, hex- Answer: 6
hept- Answer: 7
oct- Answer: 8
non- Answer: 9
IUPAC RULES Answer: IUPAC Rules:
1) Find the longest carbon chain.
• If there is a tie, the one with the most substituents is the parent chain.
2) The terminal carbon closest to a substituent is numbered #1.
• If there is a tie, look at the second substituent.
3) Order the substituents alphabetically and give each one a number to match the carbon to
which it is attached
4) If more than one of the same substituent is present, use the prefixes di, tri, tetra, etc. (i.e., 2,2-
dimethylbutane).
5) When to use hyphens:
• Hyphens are placed before and after substituent numbers, but NOT between standard prefixes.
6) Rules for alphabetizing:
• Do NOT consider the prefix when alphabetizing the substituents if:
1) it represents a number (di-, tri-, etc.) or 2) it includes a hyphen (sec-, tert-, etc.). Do
alphabetize other prefixes (isopropyl, isobutyl, etc.).
Sigma bonds Answer: First bond between 2 elements is always a sigma bond (σ), it is the head
to head overlap of two atomic orbitals
Pi bonds Answer: The second and third bonds are always
pi (π) bonds and involve side-to-side overlap
of two p orbitals. Because pi bonds require
side-to-side overlap, the atoms must be fairly close to one another
As the radius of either atom increases, the p orbitals are spread apart, resulting in less overlap
and a weaker pi bond.
Pi bonds themselves are weaker associations than are sigma bonds
Q1. Which is stronger, a sigma bond or a pi
bond? Why? Answer: Pi bonds themselves are weaker associations than are sigma bonds.
However, a double bond (one sigma bond plus one pi bond) is stronger together than a single
bond (one sigma bond only).
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
STUDY WITH CONFIDENCE!
Course Code:
Course Title: ORGANIC CHEMISTRY.
Programme:
Academic Year: 2026/2027
Duration: 2 Hours
Total Marks: 100
Candidate Instructions:
1) Write your Registration Number on every answer booklet used.
2) Answer ALL questions in Section A and ANY TWO (2) questions in Section B.
3) Read each question carefully before answering.
4) Begin each question on a new page.
5) The marks for each question are indicated in brackets.
6) This paper consists of several printed pages, including this page.
7) Ensure your copy is complete before the examination begins.
8) Unauthorized materials and communication with other candidates are not permitted.
Turn Over.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,Alkane Answer: a hydrocarbon containing only single covalent bonds
Ketone Answer: An organic compound with a carbonyl group of which the carbon atom is
bonded to two other carbons.
Alkoxy Answer: is an -OR group, an alkyl (or aryl) groupatttached to an oxygen atom.
Carbonyl Answer: carbon atom with a double bond to an oxygen atom
Hydroxyl Answer: A functional group consisting of a hydrogen atom joined to an oxygen atom
by a polar covalent bond. Molecules possessing this group are soluble in water and are called
alcohols.
Acetyl Answer: In organic chemistry, acetyl is a functional group, the acyl with chemical
formula CH3CO. It is sometimes represented by the symbol Ac (not to be confused with the
element actinium). The acetyl group contains a methyl group single-bonded to a carbonyl.
Gem-/Vic- Answer: Vicinal on 2 different adjacent carbons
Geminal- on same carbon
Tosyl Answer: a compound containing the functional group -SO3C6H4CH3, derived from
toluenesulfonic acid.
Mesyl Answer: a compound containing the functional group -SO3CH3, derived from
methanesulfonic acid.
Anhydride Answer: A functional group containing two carbonyls separated by an oxygen atom
(RCOOCOR); often the condensation dimer of a carboxylic acid.
Aryl Answer: organic halide in which the halogen atom is attached to an aromatic ring, such as
a benzene ring
Halogens (fluorine, chlorine, bromine, iodine, astatine) are nonmetal elements that are highly
electronegative and reactive.
Benzyl Answer: benzyl is the substituent or molecular fragment possessing the structure
C6H5CH2-. Benzyl features a benzene ring attached to a CH2 group.
Vinyl Answer: vinyl or ethenyl is the functional group −CH=CH2, namely the ethylene (IUPAC
ethene) molecule (H2C=CH2) minus one hydrogen atom. The name is also used for any
compound containing that group, namely R−CH=CH2 where R is any other group of atoms.
Allyl Answer: An allyl group is a substituent with the structural formula H2C=CH-CH2R,
where R is the rest of the molecule
Nitrile Answer: A nitrile is an organic chemical that contains a cyano functional group
(subunit), CN-, in which the carbon and nitrogen atoms have a triple bond i.e. C≡N-. The
general chemical formula of a nitrile is RCN, where R is the organic group.
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
,Epoxide Answer: `
Enamine/Imine Answer: An enamine is an unsaturated compound derived by the condensation
of an aldehyde or ketone with a secondary amine. Enamines are considered to be nitrogen
analogs of enols. If one of the nitrogen substituents is a hydrogen atom, H, it is the tautomeric
form of an imine.
Acyl Answer: a functional group derived by the removal of one or more hydroxyl groups from
an oxoacid,[1] including inorganic acids. It contains a double bonded oxygen atom and an alkyl
group.
Aliphatic Answer: In organic chemistry, hydrocarbons (compounds composed of carbon and
hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds also
known as non-aromatic compounds.
Aliphatics can be cyclic, but only aromatic compounds contain an especially stable ring of
atoms, such as benzene.
Aliphatic compounds can be saturated, like Hexane, or unsaturated, like Hexene and Hexyne.
Open-chain compounds (whether straight or branched) contain no rings of any type, and are thus
aliphatic.
Sulphone Answer: an organic compound containing a sulfonyl group linking two organic
groups.
Nitro Answer: Nitro compounds are organic compounds that contain one or more nitro
functional groups (−NO2). The nitro group is one of the most common explosophores
(functional group that makes a compound explosive) used globally. The nitro group is also
strongly electron-withdrawing
Acetal Answer: An acetal is a functional group with the following connectivity R2C(OR')2,
where both R' groups are organic fragments.
Ketal Answer: term ketal is sometimes used to identify structures associated with ketones rather
than aldehydes and, historically, the term acetal was used specifically for the aldehyde cases.
Hemiacetal Answer: A functional group that contains a carbon atom bonded to one -OR group,
one -OH group, an alkyl chain, and a hydrogen atom.
Hemiketal Answer: A carbon atom bonded to two alkyl groups, an -OR group, and an -OH
group
Meth Answer: 1
eth Answer: 2
prop Answer: 3
but- Answer: 4
pent- Answer: 5
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3
, hex- Answer: 6
hept- Answer: 7
oct- Answer: 8
non- Answer: 9
IUPAC RULES Answer: IUPAC Rules:
1) Find the longest carbon chain.
• If there is a tie, the one with the most substituents is the parent chain.
2) The terminal carbon closest to a substituent is numbered #1.
• If there is a tie, look at the second substituent.
3) Order the substituents alphabetically and give each one a number to match the carbon to
which it is attached
4) If more than one of the same substituent is present, use the prefixes di, tri, tetra, etc. (i.e., 2,2-
dimethylbutane).
5) When to use hyphens:
• Hyphens are placed before and after substituent numbers, but NOT between standard prefixes.
6) Rules for alphabetizing:
• Do NOT consider the prefix when alphabetizing the substituents if:
1) it represents a number (di-, tri-, etc.) or 2) it includes a hyphen (sec-, tert-, etc.). Do
alphabetize other prefixes (isopropyl, isobutyl, etc.).
Sigma bonds Answer: First bond between 2 elements is always a sigma bond (σ), it is the head
to head overlap of two atomic orbitals
Pi bonds Answer: The second and third bonds are always
pi (π) bonds and involve side-to-side overlap
of two p orbitals. Because pi bonds require
side-to-side overlap, the atoms must be fairly close to one another
As the radius of either atom increases, the p orbitals are spread apart, resulting in less overlap
and a weaker pi bond.
Pi bonds themselves are weaker associations than are sigma bonds
Q1. Which is stronger, a sigma bond or a pi
bond? Why? Answer: Pi bonds themselves are weaker associations than are sigma bonds.
However, a double bond (one sigma bond plus one pi bond) is stronger together than a single
bond (one sigma bond only).
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
