A mixture of iodine and sulphur crystals can be separated by treatment with?
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(B)
carbon (IV) sulphide to filter off iodine
2
Sieving is a technique used to separate mixture containing solid particles of
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(C)
different sizes
3
Which of the following compounds is composed of Al, Si, O and H?
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(C)
Clay
4
50 cm3 of carbon (II) oxide was exploded with 150 cm3 of air containing 20% oxygen by volume. Which of the reactants was in excess?
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(C)
Oxygen
5
How many moles of HCl will be required to react with potassium heptaoxodichromate (VI) to produce 3 moles of chlorine?
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(A)
14
6
The ratio of the initial to final pressure of a given mass of gas is 1:1.5. Calculate the final volume of the gas if the initial volume was 300 cm3 at the same temperature
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(B)
200 cm3
7
The partial pressure of oxygen in a sample of air is 452 mm Hg and the total pressure is 780 mm Hg. What is the mole fraction of oxygen?
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(B)
0.579
8
The fundamental difference between the three states of matter is the
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(D)
degree of movement of their particles
9
Which of the following statement is correct about the periodic table?
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(B)
The valence electron of the elements in the same period increase progressively across the period
10
The electron configuration of \(_{22}X^{2+}\) ion is
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(D)
1s2 2s22p6 3s2 3p6 3d2
11
Which of the following types of bonding does not involve the formation of new substance?
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(A)
Metallic
12
The knowledge of half-life can be used to
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(B)
detect an element
13
The shapes of CO\(_2\), H\(_2\)O and CH\(_4\) respectively are
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(C)
linear, bent and tetrahedral
14
The distance between the nuclei of chlorine atoms in a chlorine molecule is 0.194 mm. The atomic radius of chlorine atom is
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(A)
0.097 mm
15
The noble gas, argon,is used for
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(A)
electric arc welding
16
A side effect of soft water is that
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(C)
it attacks lead contained in pipes
17
Water molecule can be ligands especially when they are bonded to
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(C)
transition metals
18
The air pollutant unknown in nature is
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(D)
DDT
19
1.0 dm3 of distilled water was used to wash 2.0g of a precipitate of AgCl. If the solubility product of AgCl is 2.0 x 10\({^-10}\)moldm-6, what quantity of silver was lost in the process?
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(D)
1.414 * 10-5mol dm-3
20
Hydration of ions in solution is associated with
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(D)
liberation of heat
21
HCl(aq) + H\(_2\)O(l) → H\(_3\)O+(aq) + Cl\(^-\)(aq)
In the reaction above, Cl\(^-\)(aq) is the
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(C)
conjugate base
22
In which order are the following salts sensitive to light?
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(D)
AgCl > AgBr > Agl
23
The pOH of a solution of 0.25 mol dm\(^{-3}\) of hydrochloric acid is
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(B)
13.40
24
MnO\(_{4(aq)}^{-1}\) + 8H\(^+ _{(aq)}\) + Y → Mn\(^{2+} _{(aq)}\) + 4H\(_2\)O\(_{(l)}\)
Y in the equation above represents
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(C)
5e-
25
(1/2)Zn2+(aq) + e- → (1/2) Zn(s)
In the reaction above, calculate the quantity of electricity required to discharge zinc.
[F = 96 500 C mol-1]
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(C)
9.650 x 104C
26
Given that M is the mass of substance deposited in an electrolysis and Q the quantity of electricity consumed, then Faraday's law can be written as
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(D)
M = QZ
27
0.46g of ethanol when burned raised the temperature of 50g of water by 14.3K. Calculate the heat of combustion of ethanol.
[C = 12, O = 16, H = 1, Specific heat capacity of water = 4.2 jg-1K-1]
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(C)
-300 KJ mol-1
28
Powdered marble reacts faster with hydrochloric acid solution than the granular form because the powdered form has
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(C)
larger surface area
29
N2(g) + O2(g) ↔ 2NO(g); ΔH = + 180.6 kJ mol-1
In the reaction above, increase in temperature will
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(B)
increase in the yield of NO
30
For a reaction in equilibrium, the species involved in the equilibrium constant expression are
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(D)
gaseous and dissolved species
31
A phenomenon where an element exist in different forms in the same physical state is known as
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(C)
allotropy
32
The substance often used for vulcanization of rubber is
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(C)
sulphur
33
A gas that is not associated with global warming is
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(D)
H2
34
The refreshing and characteristic taste of soda water and other soft drinks is as a result of the presence in them of
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(A)
carbon (IV) oxide
35
A form of carbon used for absorbing poisonous gases and purification of noble gases is
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(A)
wood charcoal
36
Synthesis gas is a mixture of
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(D)
CO and H2
37
Potassium vapour burns with a
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(C)
violet flame
38
A common characteristics of copper and silver in their usage as coinage metals is that they
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(B)
are not easily oxidized
39
Haematite is an ore of
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(C)
iron
40
The least easily oxidized of the metals below is?
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(C)
Zn
41
The repeating unit in natural rubber is
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(B)
isoprene
42
Unsaturated organic compounds are identified by decolourization of
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(B)
bromine water and acidified potassium tetraoxomanganate (VII) solution
43
The conditions necessary for the extraction of a water molecule from two molecules of ethanol are
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(C)
excess acid and a higher temperature
44
The chlorinated alkane often used industrially to remove grease is
