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ICH602S - INORGANIC CHEMISTRY - 1ST OPP - JANUARY 2024 |
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nAmlBIA UnlVERSITY
OF SCIEnCE AnDTECHnOLOGY
Facultyof Health, Natural
ResourcesandApplied
Sciences
School of Natural and Applied
Sciences
Department of Biology,
Chemistry and Physics
QUALIFICATION : BACHELOR OF SCIENCE
QUALIFICATION CODE: 07BOSC
COURSE:INORGANIC CHEMISTRY
DATE: NOVEMBER 2024
DURATION: 3 HOURS
13Jackson Kaujeua Street
Private Bag 13388
Windhoek
NAMIBIA
T: •264 61 207 2012
F: •264 61 207 9012
E: dbcp@nust.na
W: www.nust.na
LEVEL: 6
COURSECODE: ICH602S
SESSION: 1
MARKS: 100
FIRST OPPORTUNITY: QUESTION PAPER
EXAMINER:
MODERATOR:
Dr Euodia Hess
Prof Habauka Kwaambwa
INSTRUCTIONS
1. Answer all questions on the separate answer sheet.
2. Please write neatly and legibly.
3. Do not use the left side margin of the exam paper. This must be allowed for the
examiner.
4. No books, notes and other additional aids are allowed.
5. Mark all answers clearly with their respective question numbers.
PERMISSIBLE MATERIALS:
1. Non-Programmable Calculator
ATTACHMENTS
1. List of useful constants
2. Periodic Table
This paper consists of 7 pages including this front page
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SECTION A: MULTIPLE CHOICE
[40 MARKS]
QUESTION 1:
There are 20 multiple choice questions in this section. Each question carries 2 marks.
1.1 How many sigma (o) bonds and pi (n) bonds are in carbon monoxide?
A) Three a, zero n.
B) Two o, one n.
C) One a, two n.
D) None of the above.
1.2 What is the hybridization of the central nitrogen atom in N2O?
A) sp2
B) Sp
C) sp3
D) sp3d
1.3 Which of the following does not contain at least one pi bond?
A) CO
B) H2N
C) C3Hs
D) C2H2
1.4 What is the hybridization
geometry?
A) sp2
of the central atom in a molecule with a tetrahedral
molecular
B) sp3
C) sp4
D) sp
1.5 What is the molecular geometry around a central atom that is sp2 hybridized, has three sigma
bonds, and one pi bond
A) Trigonal bipyramidal
B) Tetrahedral
C) Square planar
D) Trigonal-planar
1.6 Atomic orbitals combine most effectively to form molecular orbitals when
A) The atomic orbitals have similar energies.
B) Only d-orbitals are used in bonding.
C) Atoms have an equal number of valence electrons
D) Electrons in the orbitals have the same spin.
1.7 All of the following molecules or ions can act as polydentate ligands EXCEPT__ .
A) acetylacetate ion; CH3COCHCOCH3-
B) oxalate ion; C2O/-
C) ethylenediamine; H2NCH2CH2NH2
D) dimethylamine; (CH3)iNH2
1.8 In which of the following complexes does the transition metal have a d8 configuration?
A) Cu(H2O)/+
B) PtCJ/-
C) Fe(CN)63-
Inorganic Chemistry (ICH602S)
1s1 opportunity November 2024
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D) Ni(CO)4
1.9 How many d electrons are present on the metal ion in the complex ion CoCJ35-7
A) 8
B) 6
C) 10
D) 7
1.10 Which of the following will not act as a ligand to a transition metal cation?
A) CN-
B) H3O+
C) 02
D) PH3
1.11 What is the oxidation state of molybdenum in [Mo(H2O)sOH]Ch?
A) +3
B) +2
C) +6
D) +4
1.12 In which of the following complexes does the transition metal have a d8 configuration?
A) PtCI/-
B) Cu(H2O)/+
C) Fe(CN)G3-
D) Ni(CO)4
1.13 What is the name of the compound having the formula K2[PtCl4)?
A) Potassium tetrachloroplatinate(II)
B) Potassium chloroplatinate(II)
C) Dipotassium tetrachloroplatnum(II)
D) Potassium chloroplatinate(IV)
1.14 What is the name of the compound having the formula [Cr(en)i(H2Oh]SO4?
A) Dihydroxydiethlyenediamminechromate(II) sulfate
B) diaquabis(ethylenediamine)sulfatochromate(IV)
C) Diaquabis(ethylenediamine)chromium(II) sulfate
D) Diaquabis(ethylenediamine)sulfatochromium(II)
1.15 Below is a list of formulas for complex compounds; each is matched with its name.
One formula/name combination contains an error. Which one?
A) [Co(en)iBr2]Br/dibromobis(ethylenediamine)cobalt(III) bromide
B) [Fe(NH3)5(OH2)]Clipentaammineaquairon(ll1) chloride
C) [Cr(NH3}3(OH)3]/ triamminetrihydroxochromate(III)
D) [Ni(en)3](NO3)i / tris(ethylenediamine)nickel(II) nitrate
1.16 As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PH3,
SO3,HCI, and CO2?
A) HCI only
B) SO3and HCI
C) SO3and CO2
D) PH3and HCI
Inorganic Chemistry (ICH602S)
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1.17 Which of the following molecules is expected to form hydrogen bonds in the pure liquid or solid
phase: ethanol (CH3CH2OH)a, cetic acid (CH3CO2H)a, cetaldehyde (CH3CHO),and dimethyl ether
(CH3QCH3)?
A) ethanol and dimethyl ether
B) acetic acid and acetaldehyde
C) dimethyl ether and acetic acid
D) ethanol and acetic acid
1.18 In a water molecule forms a hydrogen bond with another water molecule, which atoms are
involved in the interaction?
A) An oxygen and a hydrogen from the same molecule
B) An oxygen from one molecule and an oxygen from the other molecule
C) A hydrogen from one molecule and a hydrogen from the other molecule
D) A hydrogen from one molecule and an oxygen from the other molecule
1.19 Nickel has a face-centered cubic cell, and its density is 8.90 g/cm3. What is the radius (in pm) of
a nickel atom?
A) 125 pm
B) 225 pm
C) 88.2 pm
D) 62 pm
1.20 Rhodium crystallizes in a face-centered cubic lattice with an edge length of 380.1 pm. What is
the density of rhodium?
A) 12.4 g/cm 3
B) 13.4 g/cm 3
C) 22.4 g/cm 3
D) 32.4 g/cm 3
SECTION B: SHORT/LONG ANSWER QUESTIONS
[60 MARKS]
There are THREE questions in this section. Please answer ALL of the questions in this section.
Show clearly, where necessary, how you arrive at the answer as all working will carry marks.
QUESTION 2:
2.1 The edge length of NaCl unit cell is 564 pm. What is the density of NaCl in g/cm 3?
2.2 Redraw the table below and match the correct examples to its respective type of crystal.
Examples: NaCl; C (diamond); Sucrose; Fe; & CaF2
[20]
(10)
(10)
Type of Crystal
Example
NaCl
C (diamond)
Sucrose
Fe
CaF2
QUESTION 3:
[20]
3.1 Show if the following compounds obeys the 18 electron rule or not:
(12)
(a) Mn(CO)sCH3
(b) HMn(CO)s
(c) Cr(CGHG)z
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3.2 What hapticities are possible for the interaction of each of the following ligands with a single
d-block metal atom such as cobalt?
(8)
a) C2H4
b) Cyclopentadienyl
c) CGHG.
d) cyclooctadiene
QUESTION 4:
[20]
4.1 Use the VSEPRmodel to predict the electron and molecular geometry of the following,
molecules & ions:
(10)
a) AsH3
b) OF2
c) AICl4-
d) 13-
e) C2H4
4.2 The N2+ ion can be prepared by bombarding the N2 molecules with fast moving electrons.
Predict the following properties of N2+ molecule:
a) Using molecular orbital (MO) theory, the electron configuration.
(4)
b) Bond order
(2)
c) Magnetic properties (paramagnetic or diamagnetic)
(2)
d) Compared to N2+ molecule, is the bond order & magnetic properties the same as N2
molecule?
(2)
END OF QUESTION PAPER
Inorganic Chemistry (ICH602S)
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LISTOF USEFULCONSTANTS:
Gas constant, R = 8.3145 J ·mo1-1 · K-1 = 0.083145 dm 3 · bar· mo1-1 · K-1 = 0.08206 L atm mo1-1 · K-1
1 Pa· m3 = 1 kPa.L = 1 N ·m = 1 J
1 atm = 101 325 Pa = 760 mm Hg= 760 torr
Avogadro's Number, NA= 6.022 x 1023 mo1-1
Planck's constant, h = 6.626 x 10-34 Js
Rydberg constant, Rh= 2.18 x 10-18 J
Speed of light, c = 2.998 x 108 ms-1
Inorganic Chemistry (ICH602S)
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PERIODIC TABLE OF THE ELEMENTS
13
14
15
56 7
18
2
He
16
17 4.00260
8 9 10
n
I
Li Be
B C N 0 F Ne
(j)
6.941 9.01218
0
10.81 12.011 14.0067 15.9994 18.9984 20.179
N
11 12
13 14 15 16 17 18
Na Mg
Al Si p s Cl Ar
22.9898 24.305 3
4
5
6
7
8
9
10
11
12 26.9815 28.0855 30.9738 32.06 35.453 39.948
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
39.0983 40.08 44.9559 47.88 50.9415 51.996 54.9380 55.847 58.9332 58.69 63.546 6538 69.72 72.59 74.9216 78.96 79.904 83.8
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
Rb Sr y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
85.4678 87.62 88.9059 91.22 92.9064 95.94 (98) 101.07 102.906 106.42 107.868 112.41 114.82 118.69 121.75 127.6 126.9 131.29
0
"C
55 56 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
"C
0-,
Cs Ba Lu Hf Ta w Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
.-+
C
132.905 137.33 174.967 178.49 180.948 183.85 186107 190.2 192.22 195.08 196.967 200.59 204383 207.2 208.908 (209) (210) (222)
:;:::;i :
-<
87 88 103 104 105 106 107 108 109 110 111 112
114
116
118
z
0<
(1)
Fr Ra Lr Rf Db Sg Bh Hs Mt Uun Uuu Uub
Uuq
(223) 226.025 (260) (261) (262) (263) (264) (265) (268) (269) (272) (269)
Uuh
Uuo
3
O"
(-1, )
N
0
N
Lanthanides: 57 58 59 60 61 62 63 64 65 66 67 68 69 70
.i::,
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb
138.906 140.12 140.908 144.24 (145) 15036 151.96 157.25 158.925 162.50 161.930 167.26 166.934 173.04
Actinides:
89 90 91 92 93 94 95 96 97 98 99 100 101 102
u Ac Th Pa
Np Pu Am Cm Bk Cf Es Fm Md No
227.028 232.038 231.036 238.029 237.048 (244) (243) (247) (247) (251) (252) (257) (258) (259)