The raw materials used for the smelting of iron ore in a furnace is
Одговорити
(B)
CaCO3
2
On heating, which of the following compounds will decompose to the free metal, nitrogen (IV) oxide and oxygen?
Одговорити
(C)
AgNO3
3
The group IA metals are not found free in nature because they
Одговорити
(A)
are very reactive and unstable
4
Carbon exist naturally in the combined state as?
Одговорити
(D)
wood
5
The efficiency of a solid catalyst to increase reaction rates depends on its
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(A)
surface area
6
Dynamic equilibrium describes a situation where
Одговорити
(C)
both forward and reverse reactions proceed at the same rate
7
The ion that will give a white precipitate with aqueous NaOH and soluble in excess of the base is
Одговорити
(C)
Zn2+
8
Which of the following pairs of substance will react further with oxygen to form a higher oxide?
Одговорити
(D)
SO2 and NO
9
The characteristic colour of the flame shown when a copper salt moistened with concentrated hydrochloric acid on a platinum wire is put on bunsen burner is
Одговорити
(B)
green
10
In the industrial production of H2 from natural gas the CO2 produced along with the H2 is removed by
Одговорити
(A)
washing under pressure
11
The sulphide which is insoluble in dilute hydrochloric acid is
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(B)
CuS
12
Which of the following typically represents a photochemical reaction?
Одговорити
(D)
Conversion of silver halides to grey metallic silver
13
The gas obtained as a product of anaerobic action on organic matter buried in the earth is?
Одговорити
(B)
methane
14
Nigerian crude oil is described as light crude because of its
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(A)
low sulphur content
15
An example of aliphatic unsaturated hydrocarbon is
Одговорити
(C)
propene
16
Which of the following has an isomer?
Одговорити
(C)
C4H10
17
CH3 - CH2 - C≡CH
The hybridization in the compound above is
Одговорити
(D)
sp3 and sp
18
One mole of a hydrocarbon contains 36g of carbon and its vapour density is 20. The structure of the hydrocarbon is
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(A)
CH3C ≡ CH
19
An emulsion may be produced by shaking a detergent solution with
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(C)
palm oil
20
The products of the combustion of candle wax are?
Одговорити
(C)
carbon (IV) oxide and water
21
When 50cm\(^3\) of a saturated solution of sugar of molar mass 342 g at 40\(^o\)C was evaporated to dryness, 34.2g of dry solid was obtained. The solubility of sugar at 40\(^o\)C is
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(A)
2.0 mol dm-3
22
Which of the following results in the fall of acid rain?
Одговорити
(C)
Oxides of sulphur
23
Water has the ability to dissolve almost all substance because its molecules has a structure with
Одговорити
(B)
one positive end and one negative end
24
When a crystal was added to the clear solution of its salt, the crystal did not dissolve and the solution remained unchanged. This showed that the solution was
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(D)
saturated
25
A particle that contains 11 protons, 12 neutrons and 10 electrons is probably a
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(B)
metallic ion
26
A difference between chemical and physical change is that in a chemical change
Одговорити
(D)
a new substance is formed
27
The volume of 2.5 moles of oxygen at s.t.p is
[Molar volume of a gas at s.t.p = 22.4 dm3]
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(D)
56.0 dm3
28
Nuclear fission involves the splitting of a heavy element into two nuclei of
Одговорити
(A)
nearly equal masses with a release of energy and radiation
29
What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g?
Одговорити
(A)
62.5 g
30
The element with the electron configuration 1S\(^2\)2S\(^2\)2P\(^3\) is
Одговорити
(D)
nitrogen
31
A decrease in atomic size and an increase in nuclear charge across a period lead to
Одговорити
(C)
a decrease in electropositivity
32
The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is
If 30cm\(^3\) of gas at 50\(^0\)C is warmed to 80\(^0\)C at a fixed pressure, the fractional increase in volume is
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(B)
0.093
35
2C\(_2\)H\(_2\)(g) + 5O\(_2\)(g) → 4CO\(_2\)(g) + 2H\(_2\)O(g)
In the reaction above, the mass of carbon(IV)oxide produced on burning 78 g of ethyne is
[C =12, O = 16, H = 1]
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(A)
264 g
36
The ion that can be used as an oxidizing agent is
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(C)
ClO-
37
H\(_2\)(g) + Br\(_2\)(g) → 2HBr(g)
The above reaction is carried out at 25\(^0\)C. ΔH is -72 kJ mol-1 and ΔS is - 106 J mol-1K-1, the reaction will?
Одговорити
(B)
proceed spontaneously at the given temperature
38
Zinc and carbon rods are used as anode and cathode respectively in a
Одговорити
(A)
Leclanche cell
39
The solution that will conduct the highest amount of electricity is?
Одговорити
(B)
2.0 mol dm-3 of hydrochloric acid
40
In which of the following is the oxidation number of sulphur equal to - 2?
Одговорити
(C)
H2S
41
In the electrolysis of CuSO\(_4\)(g) using platinum electrodes, the reaction at the anode is
Одговорити
(B)
4OH- + 4e- → 2H2O + O2
42
Na\(_2\)CO\(_3\)(g) + 2HCl(aq) → 2NaCl(aq) + H\(_2\)O(l) + CO\(_2\)(g)
How many moles of sodium trioxocarbonate (IV) are there in a 25 cm\(^3\) solution which required 10cm\(^3\) of 0.05 mol dm\(^3\) hydrochloric acid solution to neutralize it?
Одговорити
(C)
0.010 mole`
43
If the heat of combustion of hydrogen is -285.8kJ,
What is the heat of formation of water?
Одговорити
(C)
-285.8 kJ
44
5SO\(_2\)(g) + 2KMnO\(_4\)(aq) + 2H\(_2\)O(l) → K\(_2\)SO\(_4\) + 2MnSO\(_4\)(aq) + 2H\(_2\)SO\(_4\)(aq)
In the reaction above, the products give a
