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ICA511S - INTRODUCTION TO CHEMISTRY - 1ST OPP - JUNE 2023 |
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n Am I BI A u n IVER s I TY
OF SCIEnCE AnDTECHnOLOGY
FACULTYOF HEALTH,NATURAL RESOURCESAND APPLIEDSCIENCES
SCHOOLOF AGRICULTUREAND NATURALRESOURCESSCIENCES
DEPARTMENTOF AGRICULTURALSCIENCESAND AGRIBUSINESS
QUALIFICATIONS:BACHELOROF SCIENCEIN AGRICULTURE
BACHELOROF SCIENCEIN HORTICULTURE
QUALIFICATIONSCODE: 07BAGA
07BHOR
LEVEL: 7
COURSECODE: ICASllS
COURSENAME: INTRODUCTION TO CHEMISTRY
SESSION:
JUNE 2023
PAPER:
THEORY
DURATION: 3 HOURS
MARKS:
120
EXAMINER:
MODERATOR:
FIRSTOPPORTUNITY EXAMINATION QUESTION PAPER
MS. PAULINA NDINELAGO NAUPU
MRS. LUCIA TUYENI-KELAO KAFIDI
INSTRUCTIONS
1. Answer all the questions.
2. Write neatly and clearly.
3. Mark all answers clearly with their respective question numbers.
4. All written work MUST be done in blue or black ink.
5. No books, notes and other additional aids are allowed.
PERMISSIBLEMATERIALS
1. Calculator
2. Examination paper
3. Examination script
THIS QUESTION PAPERCONSISTSOF 4 PAGES{ExcludingThis Front Page)
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QUESTION 1
1.1 What is the difference between precision and accuracy in measurement?
{2}
1.2 What is the difference between a significant figure and a non-significant figure?
{2}
1.3 What is the difference between a pure substance and a mixture?
{2}
[6]
QUESTION 2
2.1 Differentiate between a homogeneous mixture and a heterogeneous mixture.
{2}
2.2 What is the difference between a physical change and a chemical change?
{2}
2.3 What is an ionic bond and what charges does it form?
{2}
2.4 What is the relationship between molarity and molality?
{2}
QUESTION 3
3.1 What is the molarity of a solution that contains 0.25 moles of glucose dissolved
ml of water?
[8]
in 500
{5}
3.2 How many milliliters of a 1.5 M solution of hydrochloric acid are needed to prepare
500ml of a 0.25 M solution?
{6}
[11]
QUESTION 4
4.1 Calculate the molarity of a solution made by dissolving 23.4 g of sodium sulfate
(Na2SO4)in enough water to form 125 ml of solution.
{6}
4.2 A 25.00 ml sample of a hydrochloric acid solution of unknown concentration was
titrated with 0.100 M sodium hydroxide solution. It took 37.55 ml of the sodium
hydroxide solution to reach the endpoint.
Using this equation, HCI+ NaOH NaCl + H2O, what is the molarity of the hydrochloric
acid solution?
{6}
[12]
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QUESTIONS
Magnesium has three isotopes with mass numbers 24, 25, and 26.
5.1 Write the complete chemical symbol for each
{3}
5.1 How many neutrons are in an atom of each isotope?
{3}
5.3 Draw the ionic bond between magnesium and bromide. Clearly show how
electron are transferred/shared/lost and the resulting ions
{8}
[14]
QUESTION 6
Provide the empirical formula of the following compounds.
[8]
6.1 C4Ha
6.3 CsH100s
QUESTION 7
For each of the following identify it as either ionic or molecular compound. For ionic, indicate
the charges of each element.
[12]
7.1 H20
7.2 MgCl2
7.3 CO2
7.4 Fe203
7.5 Sr(OH)2
7.6 C6H1206
QUESTION 8
Indicate the type of each of the following chemical reactions
[5]
8.1 2Na+C'2 2NaCI
8.3 2KCI 2K + Cb
2
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QUESTION 9
Name the formula of each of the following acids
[6]
9.1 Hydrosulfuric acid
9.2 Iron (Ill) hydroxide
9.3 Hydrophosphoric acid
QUESTION 10
Balance the following chemical equations
[8]
10.1 C + SO2 CS2+ CO
10.2 Xe + F2 XeFG
10.4 FeCb + NaOH Fe(OH)3+ NaCl
QUESTION 11
Consider the following equation: 2H2S+ 302 2 SO2+ 2 H2O
11.1 How many moles of 02 are needed to combine with 8.4 moles of H2S
{5}
11.2 Starting with 9.2 moles of 02,
11.2.1 How many moles of H2Swill you need?
{5}
11.2.2 How many moles of SO2will you get?
{5}
[15]
QUESTION 12
3.2 moles of N2 reacts with 5.4 moles H2in the following chemical reaction:
N2 + 3H2 2NH3
12.1 What is the limiting reactant
{5}
12.2 How many moles of ammonia are formed
{5}
12.3 How much of the excess reactant in moles is left over?
{5}
[15]
Total Marks: 120
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11:AA
Periodic Table of the Elements
v:Si~AA
13
14
111A 1vA
M
Q
15
vA
16
v1A
M
=He 17 2
v11A
13110 14ve
3B
4B
v5e
5B
vi6e
6B
v171e
7B
8
1
1 v9111
8
10
1110
1B
I\\I 11120 ,~
2B
Al2..U...'.2.. ',
-
-9
F
11.911
17
Cl c- j 3Ul3
35
Br
.,_ ...
7UCM
-10
Ne
20.IIO
18
Ar
3A9tg.1oo141
36
Kr
Ktyplon
U.718
.i:,.
'!
---·--.· = ... I __,_ ff "KIii'... IL Gffl JL"wa•--,1t·"WPf·~«L-J"'1111-"-1-I't~1l ·-.a,_u-111•JI 11Mlt.• I 11u11
111.m
53
loclno
12uo,
85
At
54
Xe
Xenon
m.21M
86
Rn
A20a9la.8ln17o
2-22.011
- - --- ------
-- - ---
117
Ts
1 .........
(29CJ
118
aOo--g
129CJ
LaSntehralenside
Actinide
Serles
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
lanlllanum
Collum Pra,_,...,m
Pro-
Samo~um Europium Qldolnl,..
Terlllum 0,Sprollum Holmium
Erlllum
Tl111lum --
I.IMtlum
,,uos
,,0.,,1
,co.eoe
144.243
14013
,sue
,suec
,s1.2s
,sua
112.SCJO 114.m
111.259 19034
,n.osa
11091
181:::.i!ii ~lit .....5t12.::::•:u. _:=JIM::::::JI•:::::::Jti:i:·:Jlt1 ::::::::::.u..J._ltt :::uioe........1111.::..J11o..a-l11oa