NAME ___________
KEY__________________
SECTION (circle one): A01 (Codding)
Student No. ___________________________
A02 [morning](Lee) A03 [afternoon](Lee)
UNIVERSITY OF VICTORIA
Version
A
CHEMISTRY 101
Mid-Term Test 1, October 16 2009
Version
A
This test has two parts:
PART I is a multiple choice section and is worth 26 marks. The answers for the 14 questions in this
part must be coded on the optical sense form using a SOFT PENCIL.
PART II consists of written answers and is worth 24 marks. Answer these questions on this
examination paper. Answers written partially or completely in pencil cannot be re-marked.
Hand in this entire test paper AND your optical sense form (bubble sheet) at the end of the
examination period (60 minutes). The basic Sharp EL510 calculator is the only one approved
for use in Chemistry 101. A Data Sheet accompanies this test.
Marks for Written Answers
Question 1 [4]
Question 2 [4]
Question 3 [6]
Question 4 [6]
Question 5 [4]
TOTAL (/24)
Multiple Choice (/26)
Raw Score (/24)
TOTAL MARK (%)
Chemistry 101, Mid-Term Test 1
Version A
Page 2 of 9
PART I – Multiple Choice: Select the BEST response for each question below. [Total marks = 26]
1. This is exam Version A. Mark “A” as the answer to question 1 on the optical sense form.
2.
Which one of the following statements concerning orbitals is INCORRECT?
A. The 1s orbital is the same shape as the 2s orbital.
B. Each orbital in a p subshell can hold a maximum of 2 electrons.
C. The three 4p orbitals are degenerate.
D. There are a total of 9 orbitals in all of the subshells contained in the n = 3 shell.
E. The angular momentum quantum number, ℓ, determines the energy of the electron.
3.
Which of the following electron configurations is CORRECT for the ground state of the given atom?
2
5
2
3
A. S: [Ne] 2s 2p
B. P: [Ne] 3s 3d
C. Br:[Ar] 4d
10
D. Rb: [Kr] 5s
2
5
4s 4p
1
2
1
E. Ga: [Ar] 4s 4p
4.
Which of the following statements is INCORRECT?
A. Photons are the smallest packets of radiant energy.
B. An orbital is a wave function that describes the spatial distribution of electron density.
C. Electrons fill orbitals that are closest to the nucleus first.
D. An electron can have these quantum numbers: n = 3, ℓ = 3, mℓ= 0.
E. There is an uncertainty in knowing the position and momentum of an electron simultaneously.
5.
-21
-14
-35
B. 2.4 x 10-17
A. 4.3 x 10
-20
C. 9.5 x 10
10
D. 2.7 x 10
6.
3
If an α particle weighs 6.64 x 10 kg and is travelling at 4.1 x 10 m s-1, what is the de Broglie
wavelength (in m) associated with the α particle
E. 4.1 x 10
Which of the following has the largest radius?
A. Cl-
B. Ar
C. Sc3+
D. K+
3-
E. P
Chemistry 101, Mid-Term Test 1
7.
Version A
Page 3 of 9
Which ONE of the following statements is INCORRECT?
A. The atomic radius decreases from left to right through a period of elements.
B. Cations are larger than the atoms from which they are formed.
C. The metallic character of elements decreases from left to right through a period of elements.
D. The ionization energy increases from left to right through a period of elements.
E. The atomic radius increases down the periodic table.
8.
9.
The effective nuclear charge experienced by the valence electron of a sodium atom is:
A. 10< Zeff <11
B. 9< Zeff <10
D. 0< Zeff <1
E. Zeff = 0
C. 1< Zeff <2
Which ONE of the following is INCORRECT?
A. Within a given subshell each orbital is usually filled by a single electron before any orbital has two
electrons.
B. When a metallic element unites with a nonmetallic element, electrons are lost by atoms of the metal
and gained by atoms of the nonmetals
C. The noble gas atoms have completely filled p orbitals.
2+
D. The ionization energy of Ca+ is greater than that for Ca .
E. Ba2+ is smaller than Ba+.
10. Which of the following has the most unpaired electrons Na, Mn2+, S, N, Ar?
A. Na
B. Mn2+
C. S
D. N
E. Ar
11. Which of the following has the smallest value of the first ionization energy:
Ar, Cs, N, Ba, Rb?
A. Ar
B. Cs
C. N
D. Ba
E. Rb
12. Of the compounds below, __________ has the largest lattice energy.
A. KF
B. KCl
C. RbCl
D. RbBr
E. RbF
Chemistry 101, Mid-Term Test 1
Version A
Page 4 of 9
13. Which ONE of the following statements is INCORRECT?
A. Bonds between like atoms are nonpolar bonds.
B. Polar bonds are caused by the bonding pair of electrons being attracted more to one atom than the
other.
C. In a Lewis structure, the number of valence electrons shown is increased by one for each negative
charge.
D. Two electrons involved in a bond produce a double bond.
E. In a Lewis structure, usually each atom acquires an outer-shell octet of electrons; H has 2 outer shell
electrons
14. Which of the following descriptive combinations of atoms in a bond and type of bond is CORRECT?
i. CsF, polar covalent
iv. CF4, ionic
ii. F2, nonpolar covalent
iii. ICl, polar covalent
A. i
B. i and ii
D. ii and iv
E. iv
C. ii and iii
Chemistry 101, Mid-Term Test 1
Version A
Page 5 of 9
Part II written answers to questions:
Write your answers directly on this test paper. Show all your work.
Hand in the entire test paper at the end of the test period. [Total marks = 24]
4 marks
1. [3] Complete the following table by filling in the blank spaces with a valid quantum number or orbital
name
n
ℓ
mℓ
Orbital name
4
3
Any value
between -3 and
+3
4f
3
1
0
3p
5
2
Any value
between -2 and
+2
5d
6
0
0
6s
[1] a). Sketch one orbital that has ℓ = 2
Any one of these five orbitals is acceptable. The student does not have to label axes or name the orbital. The
mark will be awarded for having 4 lobes or having the two lobes plus ring structure of the dz2 orbital
Chemistry 101, Mid-Term Test 1
Version A
Page 6 of 9
4 marks
2.
Consider the energy levels in the hydrogen atom as diagrammed below.
[2] a) What is the frequency of the light involved in the transition labeled E? .
E is from ni =3 to nf = 4
From data sheet: ν = -3.29 x 1015 s-1 {1/nf2 – 1/ni2} = -3.29 x 1015 s-1 {1/42 – 1/32)
= -3.29 x 1015 s-1 {1/16 – 1/9) = -3.29 x 1015 s-1 (-0.049)= 1.60 x 1014s-1
[1] b) How many of the labeled transitions leave the hydrogen atom in an excited state?
Five (all of the transitions)
[1] c) What are the n values for the transition (labeled or unlabeled) that corresponds to the ionization energy
for the hydrogen atom.
From n = 1 to n = ∞
Chemistry 101, Mid-Term Test 1
Version A
Page 7 of 9
6 marks
3.
Consider these two possible connectivities for the molecule H3NO:
[3] a). Complete the Lewis structure for each of these two possible skeletal structures. There is only one
valid Lewis structure for each skeleton shown above.
Structure 1:
H
..
H-N-O-H
.. ..
Structure 2:
H
..
H-O-N-H
.. ..
[2] b) Calculate the formal charges on the N and O atoms in each of your structures in part (a) above. Show
your work for full marks.
Structure 1:
N: formal charge = 5 - {2 + ½ (6)} = 0
O: formal charge = 6 – {4 + ½ (4)} = 0
Structure 2:
N: formal charge = 5 – {4 + ½ (4)} = -1
O: formal charge = 6 – {2 + ½ (6)} = +1
[1] c) Based on the formal charges, draw a circle around the structure in (a) that represents the best
connectivity.
H
..
H-N-O-H
.. ..
Chemistry 101, Mid-Term Test 1
6 marks
4. [4] a)
O
..
N
..
O
..
..
..
O
..
..
O
..
N
O
..
..
H
..
..
O
..
..
O
..
N
..
O
..
formal charge on O on left: 6 – {2+½(6)} = +1
formal charge on N: 5 – {0+½(8)} = +1
formal charge on other O : 6 – {6+½(2)} = -1
formal charge on O on left: 6 – {4+½(4) = 0
formal charge on N: 5 – {0+½(8)} = +1
formal charge on double bonded O: 6 – {4 +½(4)} = 0
formal charge on single bonded O: 6 – {6+½(2)} = -1
same as directly above
..
H
Page 8 of 9
Write three possible resonance structures for nitrous acid, H-O-NO2.
O
The connections are: H-O-N-O
..
H
Version A
..
..
O
[2] b) Based on formal charges, circle the structure makes the least contribution to the resonance
hybrid. EXPLAIN why this structure does not contribute.
This structure has a positive formal charge on one of the O atoms or has a formal charge on each of the 4
atoms.
Chemistry 101, Mid-Term Test 1
4 marks
5. [3] a)
Version A
Page 9 of 9
Three elements A, B, and C have the following atomic radii: 102, 130 and 196 pm. These
elements have the electron configurations in the table below. Use your knowledge of trends in
atomic radii to match the electron configuration with the correct atomic radius.
Electron configuration
2
2
6
2
2
2
6
2
2
2
6
2
Atom A: 1s 2s 2p 3s 3p
Atomic radius
Sulfur, smallest 1.02A
4
Magnesium 1.30A
Atom B: 1s 2s 2p 3s
6
Atom C: 1s 2s 2p 3s 3p 4s
1
Potassium, largest 1.96A
[1] b) Which atom would you expect to have the largest positive first ionization energy, I1?
Atom A or sulfur
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