 |
ICA511S - INTRODUCTION TO CHEMISTRY - 2ND OPP - JUNE 2024 |
|
|
1 Page 1 |
▲back to top |
n Am I BI A u n IVER s I TY
OF SCIEnCE AnOTECHnOLOGY
FACULTYOF HEALTH,NATURALRESOURCESAND APPLIEDSCIENCES
SCHOOLOF AGRICULTUREAND NATURALRESOURCESSCIENCES
DEPARTMENTOF AGRICULTURALSCIENCESAND AGRIBUSINESS
QUALIFICATIONS:BACHELOROF SCIENCEIN AGRICULTURE
BACHELOROF SCIENCEIN HORTICULTURE
QUALIFICATIONSCODE: 07BAGA
07BHOR
LEVEL:7
COURSECODE: ICA511S
COURSENAME: INTRODUCTION TO CHEMISTRY
DATE: JULY 2024
PAPER:2
DURATION: 3 HOURS
MARKS: 100
SECONDOPPORTUNITY/ SUPPLEMENTARYEXAMINATION QUESTION PAPER
EXAMINER:
MS. PAULINA NDINELAGO NAUPU
MODERATOR: 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)
0
|
|
2 Page 2 |
▲back to top |
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}
1.4 Differentiate between a homogeneous mixture and a heterogeneous mixture.
{2}
1.5 What is the difference between an electrolyte and non-electrolyte substance?
{4}
[12]
QUESTION 2
Provide the empirical formula of the following compounds.
2.1 (4Hs
2.2 (3N12
2.3 CsH100s
2.4 P3Ns
[2]
[2]
[2]
[2]
[8]
QUESTION 3
For each of the following identify it as either ionic or molecular compound. For ionic,
indicate the charges of each element.
3.1 H20
[2]
3.2 MgCli
[2]
3.3 CO2
[2]
3.4 Fe203
[2]
3.5 Sr(OH)2
[2]
3.6 C5H1206
[2]
[12]
1
|
|
3 Page 3 |
▲back to top |
QUESTION 4
4.1 Consider copper {II) bromide CuBr2,calculate the percentage of copper and
bromide
{6}
4.2 Calculate the percentage composition of carbon in these substances.
C12H22O1a1nd CsH9NO2
{8}
4.2 What mass of oxygen gas is required to completely react with 25.0 grams of iron
to produce iron (Ill) oxide, Fe2O3according to the following balanced equation:
4Fe + 302 2Fe2O3?
{6}
[20]
QUESTION 5
Balance the following equations
5.1 Fe2($04)3
K2$O4+ Fe (OH)3
[2]
5.2
[2]
5.3
[2]
[6]
QUESTION 6
Consider the following equation: 2H2S+ 302 2 SO2+ 2 H2O.
6.1 How many moles of 02 are needed to combine with 8.4 moles of H2S.
{4}
6.2 Starting with 9.2 moles of 02. How many moles of H2Swill you need?
{4}
6.3 How many moles of SO2will you get?
{4}
[12]
2
|
|
4 Page 4 |
▲back to top |
QUESTION 7
30g of C3Hsburns in air to produce 70g of CO2using the following reaction C3Hs+ 502
3CO2 +4H2O.
7.1 Calculate the theoretical yield
{4}
7.2 Calculate the percent yield
{3}
[7]
QUESTION 8
2 moles of propane react with 8 moles of oxygen gas in a combustion reaction in the
following equation: lC3Hs +
3CO2+ 4H2O.
8.1 What is the limiting reactant
{7}
8.2 How many moles of carbon dioxide are formed
{4}
8.3 How much of the excess reactant is left over?
{6}
[17]
QUESTION 9
Write the molecular formula of each of the following acids.
9.1 Hydrosulfuric acid
[2]
9.2 Iron (Ill) hydroxide
[2]
9.3 Hydrophosphoric acid
[2]
[6]
Total Marks:
100
3
|
|
5 Page 5 |
▲back to top |
PERIODICTABLEOF THE ELEMENTS
18
l
2
H
1.00794 2
13
14
15
He
16
17 4.00260
34
5
6
7
8 9 10
Li Be
B C N 0 F Ne
6.941 9.01218
10.81 12.01 I 14.0067 15.9994 18.9984 20.179
11 12
Na Mg
22.9898 24.305 3
4
5
6
13 14 15 16 17 18
Al Si p s Cl Ar
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
.i::,.
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
132.905 137.33 174.967 178.49 180.948 183.85 186207 190.2 192.22 195.08 196.967 200.59 204383 207.2 208.908 (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
(223) 226.025 (260) (261) (262) (263} (264) (265) '268) (269) (272) (269)
Uuh
Uuo
Lanthanides: 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
138.906 140.12 140.908 144.24 (145} 150.36 151.96 157.25 158.925 162.50 161.930 167.26 166.934 173.04
Actinides:
89 90 91 92 93 94 95 96 97 98 99 100 101 102
Ac Th Pa u 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) (2S9)