p NAMIBIA UNIVERSITY OF SCIENCE AND TECHNOLOGY

FACULTY OF HEALTH AND APPLIED SCIENCES

DEPARTMENT OF NATURAL AND APPLIED SCIENCES

QUALIFICATION: BACHELOR OF SCIENCE

QUALIFICATION CODE: 07BOSC LEVEL: 5

COURSE CODE: GNC501S COURSE NAME: GENERAL CHEMISTRY 1A

SESSION: JULY 2019 PAPER: THEORY

DURATION: 3 HOURS MARKS: 100

SUPPLEMENTARY/SECOND OPPORTUNITY EXAMINATION QUESTION PAPER

EXAMINER(S) | DR. EUODIA HESS

MoperATOR: | DR. MARIUS MUTORWA

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

Pon b

P

5. No books, notes and other additional aids are allowed

PERMISSABLE MATERIALS

Non-programmable calculators

ATTACHMENTS

1. List of useful constants

2. Periodic Table

THIS QUESTION PAPER CONSISTS OF 8 PAGES

(Including this front page, list of constants and periodic table)

SECTION A [60]

QUESTION 1: Multiple Choice Questions [60]

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

3 marks.

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

Choose the best possible answer for each question, even if you think there is

another possible answer that is not given.

When naming a transition metal ion that can have more than one common ionic charge, the

numerical value of the charge is indicated by a:

A. Prefix

B. Suffix

C. Roman numeral following the name

D. Superscript after the name

In which of the following are the symbol and name for the ion given correctly?

A. Fe?* ferrous ion B. Sn** tin (Ill) ion C. Co?* cobaltous ion

D. Pb?* lead ion

What is the correct name for Sn3(POq)2?

A. tritin diphosphate

B. tin(IIl) phosphate

C. tin(Il) phosphate

D. tin(IV) phosphate

What is the correct formula for calcium dihydrogen phosphate?

A. Ca(H2PO.)2

B. CazH2POq

C. Caz2H2HPO,

D. Caa2(H2PO.)

Which one of the following Name-Formula combinations is NOT correct (is FALSE)?

A. Mercury (I) chloride, Hg2Cl2

B. Dinitrogen trioxide, N203

C. Hydrogen chloride, HCl

D. Cerium (IV) phosphate, Ceq4(PO.)3

Page 2 of 8

10.

11.

For a particular organic compound, which of the following pairs can represent the empirical

and the molecular formulas, respectively?

A. CHand CH4

B. CH and CeHe

C. CH2 and C2H2

D. CH2 and C2H3

The percent manganese in potassium manganate, K2MnOz,, is:

A. 13.2%

B. 27.9%

C. 29.0%

D. 34.8%

What external pressure must be supplied to compress 2.76 L of a gas at 298K and 0.878 atm

to 2.00 L at 298K?

A. 484 mmHg

B. 921 mmHg

C. 760 mmHg

D. 878 mmHg

At STP, 4 moles of COz gas occupies:

A. 20.4L

B. 22.4L

C. 89.6L

D. 2.24L

If 0.250 mol of He(g), 0.500 mol of Ne(g) and 0.150 mol of Ar(g) are transferred to a

previously empty 5.00 L container at 25°C, what is the final pressure in the container?

A. 4.40 atm

B. 2.86 atm

C. 5.72 atm

D. 3.81 atm

If a mixture of noble gases consists of 0.150 mole of He, 0.450 mole of Ne, and 0.300 mole

of Ar, what is the mole fraction of Ar in this mixture?

A. 0.300

B. 0.500

C. 0.667

D. 0.333

Page 3 of 8

12.

13.

14.

15.

16.

17.

A solution is prepared by dissolving 0.100 mole of HCl in 75.0 g of water. Calculate the mass

percent HCl in this solution.

A.

To what volume, mL, must 50.0 mL of 3.50 M H2SOzq be diluted in order to make 2 M H2SOq?

A.

B. 60.1

C.

D. 93.2

A solution is prepared by dissolving 20.0 g of NaOH in 750 g. of water. The molality of this

0.133%

B. 4.64%

C.

D. 4.01%

4.87%

25

87.5

solution is?

A.

B. 26.7m

C.

D. 0.667 m

Calculate the freezing point in °C of a solution containing 0.0100 mole of a non-electrolyte in

im

0.0267 m

100.0 g of water (Kr of water = 1.86 °C/m).

A. -0.186

B. +0.186

C.

D. -0.010

0.010

What is the best name for the following compound?

OO P>

CH;

2-methylcyclohexene

2-methylcyclohexene

1-methylcyclohex-2-ene

3-methylcyclohexene

The condensed structural formula for 2,2-dimethylbutane is:

A.

B.

C.

D

CH3C(CH3)2CH2CH3

CeHia CH3CH(CH3)CH(CH3)CH3

C3H7

Page 4 of 8

18. Which one of the following is the correct structural formula for cyclohexane?

A. CeéHi2

B. CsHio

C. CeHia

D. CéHi0

19. Which of the following is the general formula of the alkynes?

A. CnpHan

B. CnHn

C. ChHans2

D CnHan-2

20. What is the best name for the following compound?

A. 3-methylenehexane

. 2-propyl-1-butene A. B

C. 4-ethyl-4-pentene

D. 2-ethyl-1-pentene

SECTION B: [40]

There are FOUR questions in this section. Answer all questions. Show clearly, where necessary,

how you arrive at the answer as all working will carry marks.

Question 1 [10]

a) All alkali metals react with water to produce hydrogen gas and the corresponding metal

hydroxide. A typical reaction is that between Lithium and water:

Li (s) + H2O (I) > LiOH (aq) + H2 (g)

How many grams of Li are needed to produce 9.89 g of H2? (3)

b) Titanium is prepared by the reaction of titanium (IV) chloride with molten magnesium between

950°C and 1150 °C.

TiCl4 (g) + Mg (I) - Ti (s) + MgCle (I)

3.54 x 10’ g of TiCl4 are reacted with 1.13 x 10’ g of Mg.

(i) Calculate the theoretical yield of Ti in grams (5)

(ii) Calculate the %yield if 7.91 x 10° g of Ti are actually obtained. (2)

Page 5 of 8

Question 2

An aqueous solution that contains 571.6 g sulphuric acid (H2SOx) in one liter of solution has a

density of 1.329 gcm™. Calculate the following for the H2SO.:

(a) Molarity

(b) Mass percent

(c) Molality

(d) Mole fraction

Question 3

a) Ethylene glycol CH2(OH)CH2(OH) is a common automobile antifreeze. It is water soluble and

non-volatile (b.p 197°C). Calculate the freezing point of a solution containing 651 g of this

substance 2505 g of water. (Kr = 1.86°C/m)

b) The average osmotic pressure of seawater is about 30.0 atm at 25 °C. Calculate the molar

concentration of an aqueous solution of sucrose (C12H2201:) that is isotonic with seawater.

c) What are the factors that affect solubility?

Question 4

Give the IUPAC names for the following compounds:

(a) Write the IUPAC names of the following compounds:

(i)

NN

(iii)

Page 6 of 8

[7]

(1)

(2)

(2)

(2)

[14]

(7)

(4)

(3)

[9]

(3)

(b) State the functional group in each of the following compounds: (6)

|

‘i CH; ——c ——OH

|

CH; ——-C ——OCH; (iii)

(iv) | CHs—NH—CH2—CH3

w CAs OH

wi) CHs ——¢ —cH,

THE END

GOODLUCK

USEFUL CONSTANTS:

Gas constant, R = 8.3145 J: molt: K*+= 0.083145 dm?: bar: mol: K*= 0.08206 L atm mol?: K?

1Pa-m?=1kPa.L =1N-m =1J

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

Avogadro’s Number, Na = 6.022 x 1073 mol

Planck’s constant, h = 6.626 x 104 Js

Speed of light, c = 2.998 x 108 ms+

Page 7 of 8

(6sz) | (8sz)

| (zsz) |

(zsz) | (sz) |

(zz) |

(rz) |

(eva |

(era) [eho

Lez]6zo sez] 9€0 lez] seo zez| azo Lee

ON | PAL

| WH |

Sa | JO

| 49

| WO]

UY] ng

| dN

OQ ed

| ¥L

|

OV Ol

101 |

OOT 66

86 L6

96 56

v6 £6

76 16

06 68

‘soplUIpY

PO'ELT [PEG OO]

OZLIL |OEG' TOT]

OS'ZOI [SzZEBST]

S7LST |] 96151)

9€ 0ST] (Set)

| bo pPL |s06 OFT ZI'OrT 1906 SEI

QA

| WL}

a9 | of

|

4a |

QL |

PD |

Ag | ag |

wg! PN!

Ja |

99 |

PT OL

69 89

L9 99

$9 +9

€9 co

19 09

6S 8S

LS |

‘sepmequsy

(692) | (zz) |

(69z) |

(s9a] (sont

(oz) Ceozd]

(z9z) |

Caz] (o9z)

[szorozz] (Ezz)

ong yng

bnq qn.

| nng |

ung | WA

| SH

|

WA |

BS |

ad |]

AL |

VT |

ew oa

Sit 911

FIT cil

|

Cll |

OLL |

601 |

SOL |

LOL |

SOT |

SOI |

yOL |

col 88

£8 (ZZ) |

(OIz)| (60z) |

806807 | T20z

fEseHOz} 65°007]L96°961|

8O'S6I | 77761

| ZT O61

[LOT 981] S881

[SPE O81| 6 SLI

IL96bLI| CE LEI |SO06 Cel

Wa |

IW |

Od ld

dd} IL

|

83H |

BV |

ta TT}

sO |

Wi M

|] OL

| JH

| OT]

&&@ |

§D 98

68 +8

€8 78

18 08

6L 8L

LL OL

CL pL

€L tL

IL 9¢

iss OT

IET | G97

| HLT

| SLIZI

| 69 SIL | TX HIT |

LH TIT /898°Lo1]

ZP90I [906ZOT}

ZO'101| (86)

| $6'S6

|¥906°26] zz

16 [6S06

881 zOL8

[SLor'ss ox

I aL

qs us

|

UW |

PO] 38V}

Pd |

Wa |

OU |

OL |

OW] GN

|

17 A

4S | da

vS €s

zs 1S

0S 67

8Y LY

or cP

br €v

47 Iv

Ov 6€

SE LE

88 |

POGGL] 96°82 |

91Z6PL] 6SZL

| 7L'69 |

BESO |

OPS COT Goes

[ZEEE SS] LEBSS

TOSEG HS] 96ETS|SIPE0S!

SSLr lassebb|

80'OP |e860'6E

IM |

J |

9S) SV

|

AD] BD]

UZ] OD]

IN | 9D]

OF | UW

AD A

I] oS

|

BO] M

9€ SE

ve €£

ze L€

O€ 67

82 LZ

97 4

bz €7

TZ IZ

07 61

8H66E] ESHSE]

OOZE |

SELOOE |SS80'8Z|ST869Z]

ZI, Il

Ol 6

g L

9 c

p €

| SOfPZ

1868672 vii]

s d |

Is | Iv

SI | &N

81 Li

oI cI

1 €l

Zl LI

6LV'02 [p866°811h666 ST] L900'F1 |

T10°ZT | 13°01

8IZ10°6| 1769

oN 4

O N

D a

7a |

IT Ol

6 8

L 9

¢ v

€ 09Z00'r

¥6L00'I 3H

LI 91

SI tI

el Zz

tr

Zz 1

81 I

SINGWATH AHL AO

ATAVL O1dOMad

Page 8 of 8