I'IHI'ITIBIR UNIVERSITY

OF SCIENCE nnD TECHFIOLOGY

FACULTY OF HEALTH AND APPLIED SCIENCES

DEPARTMENT OF NATURAL AND APPLIED SCIENCES

QUALIFICATION: BACHELOR OF SCIENCE

QUALIFICATION CODE: O7BOSC LEVEL: 7

COURSE CODE: ICH6OZS COURSE NAME: INORGANIC CHEMISTRY

SESSION: NOVEMBER 2017 PAPER: THEORY

DURATION: 3 HOURS MARKS: 100

FIRST OPPORTUNITY EXAMINATION QUESTION PAPER

EXAMINER(S) DR. EUODIA HESS

MODERATOR:P ROF HABAU KA KWAAM BWA

INSTRUCTIONS

Answer ALL the questions.

Write clearly and neatly.

Number the answers clearly

All written work must be done in blue or black ink and sketches can

be done in pencil

PWI‘JE"5. No books, notes and other additional aids are allowed

THIS QUESTION PAPER CONSISTS 0F 9 PAGES (Including this front page, list of useful constants

and Periodic Table)

SECTION A [40]

QUESTION 1: Multiple Choice Questions [40]

0 There are 20 multiple choice questions in this section. Each question carries

2 marks.

0 Answer ALL questions by selecting the letter of the correct answer.

0 Choose the best possible answer for each question, even ifyou think there is

another possible answer that is not given.

1. Which of the following conditions favours the existence of a substance in the solid state?

A. High temperature

B. Low temperature

C. High thermal energy

D. Weak cohesive forces

2. Which of the following is not a characteristic of a crystalline solid?

A. Definite characteristic heat of fusion

B. Isotropic nature

C. A regular periodically repeated pattern of arrangement of constituent particles in the entire

crystal

D. A true crystal

3. Which of the following is an amorphous solid?

A. Graphite

B. Quartz Glass

C. Chrome alum

D. Silicon carbide

4. Iodine molecules are held in the crystal lattice by ?

A. London forces

B. Dipole-dipole interactions

C. Covalent bonds

D. Coulombic forces

Page 2 of 9

5. Which of the following is a network solid?

A. 502 (solid)

B. 12

C. Diamond

D. H20 (ice)

6. What is the hybridisation of the carbon atoms in ethyne, CZHZ?

A. Sp

B. spz

C. 3193

D. 31336!

E. 5193612

7. What is the electronic geometry for 5 regions of high electron density on a central atom?

A. octahedral

B. square planar

C. tetrahedral

D. trigonal bipyramidal

E. trigonal planar

8. What angle(s) are associated with a central atom that has tetrahedral electronic geometry?

A. 109.5

B. 120

C. 120 and 180

D. 90 and 120

E. 90 and 180

9. Which one of the following molecules is polar?

A. N2

B. R,

c. C12

D. CO2

E. H20

Page 3 of 9

10.

11.

12.

13.

What kind of hybrid orbitals is utilised by the carbon atom in CR; molecules?

A. Sp

B. 5p2

C. 5103

D. sp3d

E. sp3d2

The electronic geometry of the central atom in PC13 is

A. pyramidal

B. trigonal planar

C. tetrahedral

D. octahedral

E. trigonal bipyramidal

The molecular geometry of PC13 is__

A. pyramidal

B. trigonal planar

C. tetrahedral

D. octahedral

E. trigonal bipyramidal

Choose the false statement from the following:

A. A sigma bond is a bond resulting from head-on overlap of atomic orbitals.

B. A pi bond is a bond resulting from side-on overlap of atomic orbitals.

C. A double bond consists of one sigma bond and one pi bond

D. A triple bond may consist of one sigma bond and two pi bonds or of two sigma bonds and

one pi bond.

E. A carbon atom involved in a double bond may not be sp3 hybridized.

Page 4 of 9

14. How many lone pairs of electrons does the Lewis dot structure of H25 have around its central

atom and what is the shape of the molecule?

A. 0, linear

B. 0, bent

C. 1, trigonal planar

D. 2, tetrahedral

E. 2, bent

15. Number of dative bonds to central metal ion is its

A. oxidation number

B. compound number

C. dative number

D. coordination number

16. ions which are produced from ligands are

A. Cation

B. Anion

C. Complex ion

D. All of them

17. In a face centred cubic lattice the number of nearest neighbours for a given lattice point is

A. 6

B. 4

C. 8

D. 12

18. Use VSEPR theory to predict the molecular geometry of 5032—.

A. bent

B. tetrahedral

C. square planar

D. triangular planar

E. triangular pyramidal

Page 5 of 9

19. In a comparison with s-block elements, melting points of transition elements are

A. Higher

B. Lower

C. Same

D. Constant

20. Due to ligands' action of splitting colour of transition metal compound, this change occurs at

A. s-orbital

B. p-orbital

C. d -orbital

D. f-orbital

SECTION B:

QUESTION 1:

1.1 What is the coordination number of the metal in each of the following complexes?

a) [HgClalZ'

b) [ZrF8]4'

C) [Cl‘(H20)4Cl2]+

d) [Mo(CO)sBr]‘

e) [Au(CN)2]‘

1.2 What is the oxidation state of the metal in each of the following complexes?

a) ”180412"

b) [Zng]4‘

C) [Cl’(H20)4C|2]Jr

d) [MO(CO)sBr]'

e) [AU(CN)2]'

1.3 What are the geometries for complexes with coordination number 2, 4, and 6?

Page 6 of 9

[60]

[39]

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1.4 What is the name for each of the following coordination compounds?

a) K3[Cr(C204)2CI2]

b) [Ag(NH3)2]N03

c) [Cu(en)2]504

d) Cs[FeCI4]

e) (NH4)3[RhCI6]

1.5 For each of the following complex ions give the oxidation number of metal ion,

depict low-spin or high-spin configurations, give the number of unpaired

electrons in each state and tell whether or not its paramagnetic or diamagnetic.

a) [RUIHZOI6I2+

bl [NiUVihld2+

QUESTION 2:

2.1 What are the shapes of the ions H30+ and CW}? Draw the Lewis structure for each

ion.

2.2 Deduce whether nitrogen trifluoride, dichloromethane and sulfur tetrafluoride polaror non-polar. if polar, indicate the negative and positive sides of the molecule.

2.3 Identify the hybridization of the central atom in following inorganic species:

a) 3H4—

b) SF;

c) SOF4

QUESTION 3:

Calculate the amount of energy (in kJ) needed to heat 346 g of liquid water from 0°C to 182 °C.

Assume that the specific heat of water is 4.184 J/g- °C over the entire liquid range

and that the specific heat of steam is 1.99 J/g- °C ( AHvap = 40.79 kJ/mol for water).

END OF EXAMINATION

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I11]

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[10]

Page 7 of 9

USEFUL CONSTANTS:

Gas constant, R = 8.3145 J' mol‘l' K'1 = 0.083145 dm3' bar

- mol'l' K'1 = 0.08206 L atm mol'l' K“1

1Pa‘m3=1kPa.L =1N-m =1]

1 atm = 101 325 Pa = 760 mmHg = 760 torr

Avogadro's Number, NA = 6.022 x 1023 mol'1

Planck’s constant, h = 6.626 x 10‘34 J5

Speed of light, c = 2.998 x 108 ms‘1

Page 8 of 9

Page 9 of 9

PERIODICTABLEOF

THEELEMENTS

1

18

1

2

H

He

1.00794

2

‘3

14

‘5

1"

'7

4.00260

3

4

5

6

7

8

9

10

Li

Be

B

C

N

0

F

Ne

6.941

9.01218

10.81

12.011

14.0067

15999418998420.179

11

12

13

14

15

16

17

18

Na

Mg

Al

Si

P

S

Cl

Ar

22.989824.305

3

4

5

6

7

8

9

10

11

12

26.981528.0855

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

50.941551.996

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

55

56

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

Cs

Ba

Lu

Hf

Ta

W

Re

Os

Ir

Pt

Au

Hg

Tl

Pb

Bi

Po

At

Rn

132905

137.33

174.967

178.49

180.948

183.85

186207

1902

19222

195.08

196.967200.59

204.383

2072

208.908

(209)

(210)

(222)

87

88

103

104

105

106

107

108

109

110

111

112

114

116

118

Fr

Ra

Lr

Rf

Db

Sg

Bh

HS

Mt

Uun

Uuu

Uub

Uuq

Uuh

Uuo

(223)

226.025

(260)

(261)

(262)

(263)

(264)

(265)

(268)

(269)

(272)

(269)

Lanthlnidw:

57

58

59

60

61

62

63

64

65

66

67

68

69

70

La

Ce

Pr

Nd

Pm

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

138.906140.12140.90814424(145)

150.36

151.96

15725158925162.50161.930167.26166.934173.04

Actinidefl

89

90

91

92

93

94

95

96

97

98

99

100

101

102

Ac

Th

Pa

U

Np

PuAmCm

Bk

Cf

Es

Fde

No

227.028232.038231.036238.029237.048

(244)

(243)

(247)

(247)

(251)

(252)

(257)

(258)

(259)