Which of the following equimolar solutions will have the highest pH?
Отвечать
(B)
NaOH
2
Which of the following ions require the largest quantity of electricity for discharge at an electrode?
Отвечать
(D)
2.0 moles of Al3+
3
Phenolphthalein in acidic solution is
Отвечать
(C)
colourless
4
When iron is exposed to moisture and it rusts, the value of ΔG for the reaction is
Отвечать
(D)
negative
5
In which of the following reactions can the oxidation number of the nitrogen be said to have increased?
Отвечать
(A)
2NO(g) + O2(g) → 2NO2(g)
6
2H\(_2\) + O\(_2\) → 2H\(_2\)O ΔH = - 571kJ
In the equation above, how much heat will be liberated if 12.0g of hydrogen is burnt in excess oxygen?
Отвечать
(D)
-1713 kJ
7
A concentrated solution containing H\(^+\), Cu\(^{2+}\), OH\(^-\) and Cl\(^-\) was electrolyzed using platinum electrodes.
The ion that will be discharged at the cathode is?
Отвечать
(A)
Cu2+
8
When sulphur (IV) oxide is passed into a solution of sodium hydroxide for a long time, it eventually produces a solution of
Отвечать
(B)
Na2SO3
9
What is the correct IUPAC name for NO\(_{2} ^{-}\)?
Отвечать
(D)
Dioxonitrate (III) ion
10
What will happen if an aluminium spoon is used to stir a solution of iron (II) trioxonitrates (V)?
Отвечать
(A)
The spoon will be oxidized while the iron (II) ions will be reduced to the metal
11
The enzymes responsible for converting sucrose into two simple isomeric sugars is
Отвечать
(C)
invertase
12
The decolourization of purple colour of tetraoxomanganate (VII) ion is a test for
Отвечать
(A)
alkenes
13
Which of the following are structural isomers?
Отвечать
(B)
Propanal and propanone
14
In the purification of impure samples of ethyl ethanoate synthesized by esterification, concentrated sodium trioxocarbonate (IV) solution is used to remove
Отвечать
(C)
acidic impurities
15
How many hydrogen atoms does a single ring cycloalkane have less than the corresponding open-chain alkane?
Отвечать
(A)
Two
16
Equal moles of ethyne and hydrogen iodide react to give
Отвечать
(D)
CH2 = CHI
17
A substance that is used as a ripening agent for fruits is
Отвечать
(A)
ethene
18
When water boilers are used for long period of time, the solid substances left behind as scale are
Отвечать
(A)
magnesium trioxosilicate (IV) and rust
19
25cm\(^3\) of a mixture of noble gases was obtained from air after the removal of other constituents. What was the original volume of air?
Отвечать
(A)
2,500 cm3
20
The solubility curve shows the variation of solute concentration with
Отвечать
(B)
temperature
21
The air around smelting industries is likely to contain
Отвечать
(C)
H2, SO2 and CO2
22
Kerosene is commonly used to remove the red colour stain of palm oil from cloths because it
Отвечать
(C)
makes the oil evaporate easily by dissolving it
23
The gas that is the most dangerous pollutant to human is
Отвечать
(D)
hydrogen sulphide
24
Natural water collected from rivers and ponds contain oxygen, carbon (IV) oxide and
Отвечать
(A)
nitrogen
25
How many moles of limestone will be required to produce 5.6g of CaO?
[Ca = 40, C = 12, O= 16]
Отвечать
(B)
0.10 mol
26
The shape of the hydrocarbon compound CH\(_4\) is
Отвечать
(D)
tetrahedral
27
Which of these properties gives a solid its definite shape?
Отвечать
(A)
strong intermolecular attraction
28
Sugar is separated from its impurities by
Отвечать
(B)
crystallization
29
The component of an atom that contributes least to its mass is the
Отвечать
(D)
electron
30
An element will readily form an electrovalent compound if its electron configuration is
Отвечать
(A)
2, 8, 1
31
A heterogenous mixture can be defined as any mixture
Отвечать
(C)
whose composition is not uniform
32
The pressure of 100cm\(^3\) of oxygen at 35\(^0\)C is 750mmHg. What will be the volume of gas if the pressure is reduced to 100mmHg without changing the temperature?
Отвечать
(D)
750 cm3
33
I. Treatment of cancer II. Detection of leakages in water mains III. Detection of the ages of ancient tools IV. Preparation of drugs
Which combination of the above refers to the uses of radioactive isotopes?
Отвечать
(D)
I, II, III and IV
34
What is the valence shell electron configuration of the element with atomic number 17?
Отвечать
(D)
3s2 3p5
35
The density of a certain gas is 1.98gdm\(^{-3}\) at s.t.p. What is the molecular mass of the gas?
Отвечать
(A)
44.0 g
36
When pure aluminium metal is heated to red hot in the presence of nitrogen gas, the compound formed is
Отвечать
(C)
AlN
37
A dense white fume is formed when ammonia gas reacts with
Отвечать
(D)
HCl(g)
38
N\(_2\)(g) + 3H\(_2\)(g) ↔ 2NH\(_3\)(g) ΔH = - 90 kJ
In the equation above, the yield of ammonia can be decreased by
Отвечать
(C)
increase the temperature
39
The gas that can be dried using concentrated tetraoxosulphate (VI) acid is
Отвечать
(B)
Sulphur (IV) oxide
40
NH\(_4\)Cl(s) ⇌ NH\(_3\)(g) + HCl(g)
The reaction above can only attain equilibrium if
Отвечать
(C)
it is in a closed system
41
The most suitable metal that can be used as lightning conductor is?
Отвечать
(B)
copper
42
In the diagram above which of the curves illustrates Arrhenius' law?
Отвечать
(D)
X
43
The most abundant element on the earth's crust is
Отвечать
(C)
oxygen
44
Metalloids are also referred to as
Отвечать
(A)
semi-metals
45
The ores that can be concentrated by flotation are
