General Chemistry 202-NYA-05
ASSIGNMENT 3
STUDENT NAME:
Due time: Wednesday December 15th, start of class
Guidelines:
- Answer questions directly on the booklet and hand it back to the teacher before the due date.
- You may also complete this assignment electronically, but it is your responsibility to print it in time
for the due date.
- Unless major circumstances prevent it (quarantine for example), only paper versions will be
accepted. Only students who have let the teacher know in advance about these circumstances will
be allowed to submit their work online. Assignments submitted online without prior
communication will NOT be graded.
- No make-up assignment. This is the only one you will get.
- Missed deadline will lead to a 10% daily penalty until day 5, after which you will get a 0 grade.
Extensions may be given if you explain the reasons you cannot submit it on time more than 24h
before the due time.
- The teacher will answer questions about this assignment by MIO, at the end of lectures (time
permitting), and during office hours.
1) Fill in the following table: find the hybridization state of the central atom in the following
molecules. The central atom is bolded. No need to justify your answers! (12 points)
Formula Best Lewis structure Family 3D sketch Central atom
hybridization state
H2O AB2E2 sp3
Bent
CS2
SeO32-
XeO4
IF5
1/9
, General Chemistry 202-NYA-05
Questions 2-5: Which of the following statements is incorrect. Only one per question!
2) Which of the following statements is incorrect? About hybridization: (4 points)
a. Hybrid orbitals are obtained by linear combination of atomic orbitals.
b. sp2 hybrid orbitals are obtained by combining one s orbital and two p orbitals.
c. The energy of the hybrid orbitals is the energy of the lowest atomic orbital.
d. Hybridization is an amendment made to the localized electron model to reconcile it with
the atomic orbital theory.
e. Hybridization can also involve d orbitals.
3) Which of the following statements is incorrect? About molecular orbitals: (4 points)
a. Molecular orbitals (MOs) are obtained by linear combination of atomic orbitals (AOs).
b. The combination of two atomic orbitals always yields two molecular orbitals.
c. A molecular orbital describes the region of space where an electron shared by two atoms
is most likely to be found.
d. The number of molecular orbitals is always superior to the number of atomic orbitals they
were created from.
e. None of the above.
4) A (pi) bond is the result of: (4 marks)
a. The overlap of two s orbitals
b. The overlap of an s orbital and a p orbital
c. The overlap of two p orbitals along their axes
d. The sidewise overlap of two parallel p orbitals
e. The sidewise overlap of two s orbitals
5) Which of the following statements is true? (4 points)
a. All antibonding MOs are higher in energy than the atomic orbitals of which they are
composed.
b. Antibonding MOs have electron density mainly outside the space between the two nuclei.
c. Electrons are never found in an antibonding MO.
d. Both a. and b. are true.
e. Both a. and c. are true.
2/9
ASSIGNMENT 3
STUDENT NAME:
Due time: Wednesday December 15th, start of class
Guidelines:
- Answer questions directly on the booklet and hand it back to the teacher before the due date.
- You may also complete this assignment electronically, but it is your responsibility to print it in time
for the due date.
- Unless major circumstances prevent it (quarantine for example), only paper versions will be
accepted. Only students who have let the teacher know in advance about these circumstances will
be allowed to submit their work online. Assignments submitted online without prior
communication will NOT be graded.
- No make-up assignment. This is the only one you will get.
- Missed deadline will lead to a 10% daily penalty until day 5, after which you will get a 0 grade.
Extensions may be given if you explain the reasons you cannot submit it on time more than 24h
before the due time.
- The teacher will answer questions about this assignment by MIO, at the end of lectures (time
permitting), and during office hours.
1) Fill in the following table: find the hybridization state of the central atom in the following
molecules. The central atom is bolded. No need to justify your answers! (12 points)
Formula Best Lewis structure Family 3D sketch Central atom
hybridization state
H2O AB2E2 sp3
Bent
CS2
SeO32-
XeO4
IF5
1/9
, General Chemistry 202-NYA-05
Questions 2-5: Which of the following statements is incorrect. Only one per question!
2) Which of the following statements is incorrect? About hybridization: (4 points)
a. Hybrid orbitals are obtained by linear combination of atomic orbitals.
b. sp2 hybrid orbitals are obtained by combining one s orbital and two p orbitals.
c. The energy of the hybrid orbitals is the energy of the lowest atomic orbital.
d. Hybridization is an amendment made to the localized electron model to reconcile it with
the atomic orbital theory.
e. Hybridization can also involve d orbitals.
3) Which of the following statements is incorrect? About molecular orbitals: (4 points)
a. Molecular orbitals (MOs) are obtained by linear combination of atomic orbitals (AOs).
b. The combination of two atomic orbitals always yields two molecular orbitals.
c. A molecular orbital describes the region of space where an electron shared by two atoms
is most likely to be found.
d. The number of molecular orbitals is always superior to the number of atomic orbitals they
were created from.
e. None of the above.
4) A (pi) bond is the result of: (4 marks)
a. The overlap of two s orbitals
b. The overlap of an s orbital and a p orbital
c. The overlap of two p orbitals along their axes
d. The sidewise overlap of two parallel p orbitals
e. The sidewise overlap of two s orbitals
5) Which of the following statements is true? (4 points)
a. All antibonding MOs are higher in energy than the atomic orbitals of which they are
composed.
b. Antibonding MOs have electron density mainly outside the space between the two nuclei.
c. Electrons are never found in an antibonding MO.
d. Both a. and b. are true.
e. Both a. and c. are true.
2/9
