CHEM0010 EXAM QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
Which of the following concepts are required to determine the ground state
electronic configuration of the nitrogen atom?
Select one or more:
A) The de Brogile reaction
B) Hund's Rule
C) Pauli Exclusion Principle
D) Aufbau Principle
E) Schrodinger Equation
B) Hund's rule
and
C) Pauli Exclusion Principle
and
D) Aufbau Principle
- Hund's rule determines how you fill the orbitals when some orbitals are already
present
- electrons do not pair up in orbitals unless they have no alternative, and the lowest
energy configuration has all the spins parallel in separate orbitals
,- Pauli exclusion principle states that no two electrons can be in the same quantum
state
- the Aufbau principle tells us the energy order of the orbitals
What does the term 'degenerate' mean?
Select one:
A) Identical and indistinguishable
B) Of reduced stability
C) Debased and degraded
D) Not unique
E) Identical and indistinguishable in energy
E) Identical and indistinguishable in energy
- degeneracy refers to when there are multiple identical energy states that a particle or a
molecule can "choose" between
- e.g. the p-orbitals in an isolated atom are said to be degenerate because they are
identical in every way and you could drop an electron into them in three ways
The shape of the carbonate ion (CO3)2- is:
Select one:
A) Pyramidal
B) Trigonal Planar
C) T-shaped
,D) Linear
E) Tetrahedral
B) Trigonal Planar
- there are no lone pairs and three oxygens around the outside
Which of the following statements is TRUE?
Select one:
A) Resonance structures are similar molecules but with different electronic
structures
B) Resonance structures are different, but equivalent, ways of representing the
electronic structure of a molecule
C) Benzene only has a single resonance form, which is delocalised
D) Resonance structures are in very rapid equilibrium with each other
E) Single bonds can never be represented as resonance forms
B) Resonance structures are different, but equivalent, ways of representing the
electronic structure of a molecule
Water (H2O)
bond angle: 104.5 degrees
- the water molecule has a bent structure, based on the tetrahedral geometry, but the
bond angle is < 109.5 degrees due to greater lone pair repulsion
Nitrite (NO2)-
, bond angle: 115.4 degrees
- nitrite has two resonance forms, and the Lewis structure shows how 3 of its 5 valence
electrons are occupied in the bonding to the two O atoms, leaving a lone pair
- according to VSEPR theory, we ignore the double bond and treat it as a single, so
there are 3 electron pairs in total contributing to the geometry: trigonal planar, but the
bond angle is slightly less than 120 degrees due to the lone pair repulsion
What is the hybridisation of the carbon atoms in an alkane?
Select one:
A) sp3
B) sp4
C) sp
D) sp2
E) Not hybridised
A) sp3
- the geometry about the carbon atoms in alkanes is tetrahedral
- this is consistent with sp3 hybridisation
What is the hybridisation of the double bond carbon in an alkene?
Select one:
A) sp
COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
Which of the following concepts are required to determine the ground state
electronic configuration of the nitrogen atom?
Select one or more:
A) The de Brogile reaction
B) Hund's Rule
C) Pauli Exclusion Principle
D) Aufbau Principle
E) Schrodinger Equation
B) Hund's rule
and
C) Pauli Exclusion Principle
and
D) Aufbau Principle
- Hund's rule determines how you fill the orbitals when some orbitals are already
present
- electrons do not pair up in orbitals unless they have no alternative, and the lowest
energy configuration has all the spins parallel in separate orbitals
,- Pauli exclusion principle states that no two electrons can be in the same quantum
state
- the Aufbau principle tells us the energy order of the orbitals
What does the term 'degenerate' mean?
Select one:
A) Identical and indistinguishable
B) Of reduced stability
C) Debased and degraded
D) Not unique
E) Identical and indistinguishable in energy
E) Identical and indistinguishable in energy
- degeneracy refers to when there are multiple identical energy states that a particle or a
molecule can "choose" between
- e.g. the p-orbitals in an isolated atom are said to be degenerate because they are
identical in every way and you could drop an electron into them in three ways
The shape of the carbonate ion (CO3)2- is:
Select one:
A) Pyramidal
B) Trigonal Planar
C) T-shaped
,D) Linear
E) Tetrahedral
B) Trigonal Planar
- there are no lone pairs and three oxygens around the outside
Which of the following statements is TRUE?
Select one:
A) Resonance structures are similar molecules but with different electronic
structures
B) Resonance structures are different, but equivalent, ways of representing the
electronic structure of a molecule
C) Benzene only has a single resonance form, which is delocalised
D) Resonance structures are in very rapid equilibrium with each other
E) Single bonds can never be represented as resonance forms
B) Resonance structures are different, but equivalent, ways of representing the
electronic structure of a molecule
Water (H2O)
bond angle: 104.5 degrees
- the water molecule has a bent structure, based on the tetrahedral geometry, but the
bond angle is < 109.5 degrees due to greater lone pair repulsion
Nitrite (NO2)-
, bond angle: 115.4 degrees
- nitrite has two resonance forms, and the Lewis structure shows how 3 of its 5 valence
electrons are occupied in the bonding to the two O atoms, leaving a lone pair
- according to VSEPR theory, we ignore the double bond and treat it as a single, so
there are 3 electron pairs in total contributing to the geometry: trigonal planar, but the
bond angle is slightly less than 120 degrees due to the lone pair repulsion
What is the hybridisation of the carbon atoms in an alkane?
Select one:
A) sp3
B) sp4
C) sp
D) sp2
E) Not hybridised
A) sp3
- the geometry about the carbon atoms in alkanes is tetrahedral
- this is consistent with sp3 hybridisation
What is the hybridisation of the double bond carbon in an alkene?
Select one:
A) sp
