UNIT 1: INTRODUCTION TO ORGANIC CHEMISTRY | FROM
QUESTION TO PERFECTION| STUDY WITH CONFIDENCE!
Course Code:
Course Title:
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
,A double bond forms when a total of _____ electrons are shared between atoms, and a triple
bond forms when ______ electrons are shared between atoms. Answer: A double bond forms
when a total of four electrons are shared between atoms, and a triple bond forms when six
electrons are shared between atoms.
The _____ ___________ ______ is the energy required to break a covalent bond and evenly
divide the electrons from the covalent bond. Answer: The bond dissociation energy is the
energy required to break a covalent bond and evenly divide the electrons from the covalent
bond.
A Lewis (dot) structure represents chemical bonding between atoms in a molecule by depicting
each _______ _________ as a single dot. Answer: A Lewis (dot) structure represents chemical
bonding between atoms in a molecule by depicting each valence electron as a single dot.
How does the stability of atoms change as they fulfill an octet? Answer: By fulfilling an octet,
individual atoms become isoelectronic with the noble gases and gain increased stability.
An atom that gives up valence electrons becomes a positively charged anion, and an atom that
gains electrons becomes a negatively charged cation. (True or False) Answer: False. An atom
that gives up valence electrons becomes a positively charged cation, and an atom that gains
electrons becomes a negatively charged anion.
Define the octet rule. Answer: The octet rule states that individual atoms either transfer or share
valence electrons to give each atom access to eight valence electrons.
Multiple bonds [increase/decrease] the bond length. (Choose one option) Answer: Multiple
bonds decrease the bond length.
Atoms with valence electrons in higher shells farther from the nucleus have longer bond lengths.
(True or False) Answer: True. Atoms with valence electrons in higher shells farther from the
nucleus have longer bond lengths.
List the types of bonds in order of decreasing bond strength:
(A) Single bond
(B) Double bond
(C) Triple bond Answer: Correct order: C, B, A
Between atoms of the same type, the bonds, from strongest to weakest, are:
(C) Triple bond
(B) Double bond
(A) Single bond
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
,The number of valence electrons of an element often indicates the total number of covalent
bonds that the element prefers to form within molecules. (True or False) Answer: True. The
number of valence electrons of an element often indicates the total number of covalent bonds
that the element prefers to form within molecules.
An oxygen atom with a formal charge of zero has a total of _____ covalent bonds and _____
lone pairs. Answer: An oxygen atom with a formal charge of zero has a total of two covalent
bonds and two lone pairs
Which elements on the periodic table may allow more than eight valence electrons? Answer:
Elements in the third row of the periodic table (or greater) have access to d subshells that may
allow more than eight valence electrons (an expanded octet).
What is the difference between an ionic bond and a covalent bond? Answer: In an ionic bond,
one atom fully transfers one or more electrons to another, and ions are generated.
Conversely, a covalent bond is formed when atoms share electrons to achieve a full octet.
Ionic bonds are most commonly formed between a [metal/nonmetal/metalloid] and a
[metal/nonmetal/metalloid]. (Choose one option for each) Answer: Ionic bonds are most
commonly formed between a metal and a nonmetal.
Which two elements only require two valence electrons to fill their orbitals? Answer: Only
hydrogen and helium (ie, elements in the first row of the periodic table) require two valence
electrons to fill their orbitals.
The combination of ______ s atomic orbital(s) and ______ p atomic orbital(s) forms three sp^2
hybrid orbitals. Answer: The combination of one s atomic orbital and two p atomic orbitals
forms three sp2 hybrid orbitals.
Name the three possible hybrid orbitals generated by the linear combination of s and p atomic
orbitals on the same atom. Answer: The possible hybrid orbitals are sp^3, sp^2, and sp hybrid
orbitals.
Atoms that are sp^3 hybridized have three electron domains. (True or False) Answer: False.
Atoms that are sp^3 hybridized have four electron domains.
Explanation:
The number of electron domains must equal the sum of the s and p superscripts in the hybrid
orbital
The combination of one s orbital and three p orbitals results in ________ sp^3 hybrid orbitals.
Answer: The combination of one s orbital and three p orbitals (four total atomic orbitals) results
in four sp^3 hybrid orbitals.
Atoms participating in ____ triple bond(s) or _____ double bond(s) are sp hybridized. Answer:
Atoms participating in one triple bond or two double bonds are sp hybridized.
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3
, The two sp hybrid orbitals are oriented along the axis of the contributing p orbital. (True or
False) Answer: True. The two sp hybrid orbitals are oriented along the axis of the contributing p
orbital.
In a covalent bond, the more electronegative atom carries a [partial positive charge (δ+)/partial
negative charge (δ^−)], while the less electronegative atom carries a [partial positive charge
(δ^+)/partial negative charge (δ^−)]. (Choose one option for each) Answer: In a covalent bond,
the more electronegative atom carries a partial negative charge (δ^−), while the less
electronegative atom carries a partial positive charge (δ^+).
On the periodic table, electronegativity tends to increase from [left to right/right to left] across a
period and from the [top to the bottom/bottom to the top] of a group. (Choose one option for
each) Answer: On the periodic table, electronegativity tends to increase from left to right across
a period and from the bottom to the top of a group.
What are the two factors that impact the strength of the dipole moment (µ) of a bond? Answer:
The strength of a bond's dipole moment (µ) depends on:
- the magnitude of charge separation (difference in electronegativity).
- the distance of charge separation (bond length).
A dipole moment is commonly denoted by an arrow oriented with its arrowhead pointing toward
the less electronegative atom (δ^+) and its crossed tail near the more electronegative atom
(δ^−). (True or False) Answer: False. A dipole moment is commonly denoted by an arrow
oriented with its arrowhead pointing toward the more electronegative atom (δ^−) and its crossed
tail near the less electronegative atom (δ^+).
Electron-donating groups and electron-withdrawing groups can shift the electron density around
nearby atoms and bonds through the _________ ________. Answer: Electron-donating groups
and electron-withdrawing groups can shift the electron density around nearby atoms and bonds
through the inductive effect.
Atoms that tend to easily accept electrons tend to have a lower electronegativity. (True or False)
Answer: False. Atoms that tend to accept electrons tend to have a higher electronegativity.
Explanation:
Atoms that accept electrons also tend to have a higher electron affinity and a higher ionization
energy.
Match each electronegativity difference between atoms to the type of bond the atoms will form:
Electronegativity difference:
(1) Less than 0.5
(2) Between 0.5 and 1.8
(3) Greater than 1.8
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
QUESTION TO PERFECTION| STUDY WITH CONFIDENCE!
Course Code:
Course Title:
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
,A double bond forms when a total of _____ electrons are shared between atoms, and a triple
bond forms when ______ electrons are shared between atoms. Answer: A double bond forms
when a total of four electrons are shared between atoms, and a triple bond forms when six
electrons are shared between atoms.
The _____ ___________ ______ is the energy required to break a covalent bond and evenly
divide the electrons from the covalent bond. Answer: The bond dissociation energy is the
energy required to break a covalent bond and evenly divide the electrons from the covalent
bond.
A Lewis (dot) structure represents chemical bonding between atoms in a molecule by depicting
each _______ _________ as a single dot. Answer: A Lewis (dot) structure represents chemical
bonding between atoms in a molecule by depicting each valence electron as a single dot.
How does the stability of atoms change as they fulfill an octet? Answer: By fulfilling an octet,
individual atoms become isoelectronic with the noble gases and gain increased stability.
An atom that gives up valence electrons becomes a positively charged anion, and an atom that
gains electrons becomes a negatively charged cation. (True or False) Answer: False. An atom
that gives up valence electrons becomes a positively charged cation, and an atom that gains
electrons becomes a negatively charged anion.
Define the octet rule. Answer: The octet rule states that individual atoms either transfer or share
valence electrons to give each atom access to eight valence electrons.
Multiple bonds [increase/decrease] the bond length. (Choose one option) Answer: Multiple
bonds decrease the bond length.
Atoms with valence electrons in higher shells farther from the nucleus have longer bond lengths.
(True or False) Answer: True. Atoms with valence electrons in higher shells farther from the
nucleus have longer bond lengths.
List the types of bonds in order of decreasing bond strength:
(A) Single bond
(B) Double bond
(C) Triple bond Answer: Correct order: C, B, A
Between atoms of the same type, the bonds, from strongest to weakest, are:
(C) Triple bond
(B) Double bond
(A) Single bond
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
,The number of valence electrons of an element often indicates the total number of covalent
bonds that the element prefers to form within molecules. (True or False) Answer: True. The
number of valence electrons of an element often indicates the total number of covalent bonds
that the element prefers to form within molecules.
An oxygen atom with a formal charge of zero has a total of _____ covalent bonds and _____
lone pairs. Answer: An oxygen atom with a formal charge of zero has a total of two covalent
bonds and two lone pairs
Which elements on the periodic table may allow more than eight valence electrons? Answer:
Elements in the third row of the periodic table (or greater) have access to d subshells that may
allow more than eight valence electrons (an expanded octet).
What is the difference between an ionic bond and a covalent bond? Answer: In an ionic bond,
one atom fully transfers one or more electrons to another, and ions are generated.
Conversely, a covalent bond is formed when atoms share electrons to achieve a full octet.
Ionic bonds are most commonly formed between a [metal/nonmetal/metalloid] and a
[metal/nonmetal/metalloid]. (Choose one option for each) Answer: Ionic bonds are most
commonly formed between a metal and a nonmetal.
Which two elements only require two valence electrons to fill their orbitals? Answer: Only
hydrogen and helium (ie, elements in the first row of the periodic table) require two valence
electrons to fill their orbitals.
The combination of ______ s atomic orbital(s) and ______ p atomic orbital(s) forms three sp^2
hybrid orbitals. Answer: The combination of one s atomic orbital and two p atomic orbitals
forms three sp2 hybrid orbitals.
Name the three possible hybrid orbitals generated by the linear combination of s and p atomic
orbitals on the same atom. Answer: The possible hybrid orbitals are sp^3, sp^2, and sp hybrid
orbitals.
Atoms that are sp^3 hybridized have three electron domains. (True or False) Answer: False.
Atoms that are sp^3 hybridized have four electron domains.
Explanation:
The number of electron domains must equal the sum of the s and p superscripts in the hybrid
orbital
The combination of one s orbital and three p orbitals results in ________ sp^3 hybrid orbitals.
Answer: The combination of one s orbital and three p orbitals (four total atomic orbitals) results
in four sp^3 hybrid orbitals.
Atoms participating in ____ triple bond(s) or _____ double bond(s) are sp hybridized. Answer:
Atoms participating in one triple bond or two double bonds are sp hybridized.
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
, The two sp hybrid orbitals are oriented along the axis of the contributing p orbital. (True or
False) Answer: True. The two sp hybrid orbitals are oriented along the axis of the contributing p
orbital.
In a covalent bond, the more electronegative atom carries a [partial positive charge (δ+)/partial
negative charge (δ^−)], while the less electronegative atom carries a [partial positive charge
(δ^+)/partial negative charge (δ^−)]. (Choose one option for each) Answer: In a covalent bond,
the more electronegative atom carries a partial negative charge (δ^−), while the less
electronegative atom carries a partial positive charge (δ^+).
On the periodic table, electronegativity tends to increase from [left to right/right to left] across a
period and from the [top to the bottom/bottom to the top] of a group. (Choose one option for
each) Answer: On the periodic table, electronegativity tends to increase from left to right across
a period and from the bottom to the top of a group.
What are the two factors that impact the strength of the dipole moment (µ) of a bond? Answer:
The strength of a bond's dipole moment (µ) depends on:
- the magnitude of charge separation (difference in electronegativity).
- the distance of charge separation (bond length).
A dipole moment is commonly denoted by an arrow oriented with its arrowhead pointing toward
the less electronegative atom (δ^+) and its crossed tail near the more electronegative atom
(δ^−). (True or False) Answer: False. A dipole moment is commonly denoted by an arrow
oriented with its arrowhead pointing toward the more electronegative atom (δ^−) and its crossed
tail near the less electronegative atom (δ^+).
Electron-donating groups and electron-withdrawing groups can shift the electron density around
nearby atoms and bonds through the _________ ________. Answer: Electron-donating groups
and electron-withdrawing groups can shift the electron density around nearby atoms and bonds
through the inductive effect.
Atoms that tend to easily accept electrons tend to have a lower electronegativity. (True or False)
Answer: False. Atoms that tend to accept electrons tend to have a higher electronegativity.
Explanation:
Atoms that accept electrons also tend to have a higher electron affinity and a higher ionization
energy.
Match each electronegativity difference between atoms to the type of bond the atoms will form:
Electronegativity difference:
(1) Less than 0.5
(2) Between 0.5 and 1.8
(3) Greater than 1.8
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
