A mixture of sand, ammonium chloride and sodium chloride is best separated by?
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(A)
sublimation followed by addition of water and filteration
2
A pure solid usually melts?
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(B)
over a narrow range of temperature
3
At the same temperature and pressure, 50 cm3 of nitrogen gas contains the same number of molecules as?
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(C)
50 cm3 of ammonia
4
8g CH4 occupies 11.2 dm3 at s.t.p. What volume would 22 g of CH3CH2CH3 occupy under the same condition?
(C = 12, H = 1)
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(B)
11.2 dm3
5
To what temperature must a gas 273 K be heated in order to double both its volume and pressure?
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(D)
1092 K
6
For a gas, the relative molecular mass is equal to 2Y. What is Y?
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(B)
The vapour density of the gas
7
The densities of two gases, X and Y, are 0.5 g dm-3 and 2.0 dm-3 respectively.
What is the rate of diffusion of X relative to Y?
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(C)
2.0
8
The shape of ammonia molecule is?
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(A)
trigonal planar
9
An increase in temperature causes an increase in the pressure of a gas because?
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(B)
the molecules of the gas bombard the walls of the container more frequently
10
The number of electrons in the valence shell of an element of atomic number 14 is?
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(D)
4
11
Which of the following physical properties decreases down a group in the periodic table?
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(D)
Electronegativity
12
Element X, Y and Z belong to a groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ3?
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(C)
XZ is electrovalent and YZ3 is covalent
13
A solid that absorbs water from he atmosphere and forms an aqueous solution is?
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(C)
deliquescent
14
A major effect of oil pollution in coastal waters is the?
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(A)
destruction of marine life
15
Sodium chloride has no solubility product value because of its?
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(B)
high solubility
16
The solubility, in moles per dm3 of 20.2 g of potassium trioxonitrate (V) dissolve in 100 g of the resulting mixture is?
(K = 39, O = 16, N =14).
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(D)
2.00
17
Which of the following atoms represents deuterium?
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(C)
No protons = 1, No of neutrons = 1, No of electrons = 1
18
A few drops of concentrated HCI are added to about 10cm3 of a solution of pH 3.4. The pH of the resulting mixtures is?
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(A)
less than 3.4
19
Which of the following compounds is a base?
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(B)
CaO
20
20 cm\(^3\) of a 2.0 M solution of ethanoic acid was added to excess of 0.05 M sodium hydroxide. The mass of the salt produced is?
(Na = 23, C = 12, O = 16, H = 1)
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(C)
3.28 g
21
What volume of Oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?
(Molar volume of gas = 22.4 dm\(^3\), 1F = 96,500 C/mol)
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(D)
0.560 dm3
22
Crude copper could be purified by the electrolysis of concentrated copper (II) chloride if the crude copper is?
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(C)
made the anode
23
H- + H2(I)O → H2(g) + OH-(aq). From the equation above, it can be inferred that the?
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(B)
hydride ion is a reducing agent
24
An anhydride is an oxide of non-mental
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(C)
whose solution in water has a pH less than 7
25
MnO4(aq) + 8H + (aq) + 5Fe2+ → Mn2+(aq) + 4H2O(I). The oxidation number of manganese in the above reaction changed from?
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(A)
+7 to +2
26
Which of the following is TRUE of Le Chatelier's Principle for an exothermic reaction?
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(B)
Increase in temperature will cause a decrease in the equilibrium constant
27
Which of the following are produced when ammonium trioxonitrate (V) crystals are cautiously heated in a hard glass round bottomed flask?
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(A)
N2O and steam
28
Which of these metals CANNOT replace hydrogen from alkaline solutions?
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(D)
Iron
29
Clothes should be properly rinsed with water after bleaching because?
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(D)
hydrogen chloride solution is produced during bleaching
30
Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid?
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(B)
Sodium tetraoxosulphate (IV)
31
SO3 is NOT directly dissolved in water in the preparation of H2SO4 by the contact process because?
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(A)
the reaction between SO3 and water is violently exothermic
32
In an electrolytic set-up to protect iron from corrosion, the iron is?
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(A)
made cathode
33
Which of the following is NOT true of metals?
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(C)
Their oxides are acidic
34
Which of the following is the correct order of decreasing activity of the metals Fe, Ca, Al and Na?
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(B)
Na> Ca> Al> Fe
35
Which of the following compounds is NOT an isomers of 2,2 dimethylbutane?
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(A)
2-methylbutane
36
When sodium is added to ethanol, the products are?
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(D)
sodium ethoxide and hydrogen
37
The general formula of alkanoates is?
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(D)
RCOOR
38
One mole of a hydrocarbon contains 48 g of carbon. If it vapour density is 28, the hydrocarbon is?
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(B)
an alkene
39
Which of the following reagents will confirm the presence of unsaturation in a compound?
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(B)
Bromine water
40
The diagram above represents an atom of
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(A)
magnesium
41
The set-up above would be useful for determining the amount of
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(B)
water vapour in air
42
The ∆H for the reaction represented by the energy profile above is
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(D)
-50 kJ mol-1
43
In the diagram above the activation energy is represented by
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(A)
y - x
44
2HCL(ag) + CaCO3(ag) → CaCL2(ag) + H2O(1) + CO from the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate (IV) as dilute HCL is added to it?
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(D)
P
45
In the diagram above, R is a mixture of?
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(C)
potassium tetratoxomanganate (VII) and concentrated HCI
46
The IUPAC name of the compound above is
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(C)
3,3-dimethyl but -1-ene
47
Use the diagram above to answer this question. The reaction taking place in flask G is known as?
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(C)
dehydration
48
MnO4(aq) + 8H + 5Fe2+ \(\to\) Mn2+(aq) + 5Fe3+(aq) + H2O. The oxidation number of maganese in the above reaction changed from
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(A)
+7 to +2
49
which of these metals CANNOT replace hydrogen from alkaline solutions?
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(D)
Iron
50
Clothes should be properly rinsed with water after bleaching because
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(D)
hydrogen chloride solution is produced during bleaching
