A given amount of gas occupies 10.0dm\(^3\) at 4 atm and 273°C. The number of moles of the gas present is?
[Molar volume of gas at s.t.p = 22.4 dm\(^3\)]
Trả lời
(A)
0.89 mol
2
According to Charles' law, the volume of a gas becomes zero at
Trả lời
(C)
-273°C
3
A substance that is used as a ripening agent for fruits is
Trả lời
(A)
ethene
4
The Sulphide which is insoluble in dilute hydrochloric acid is
Trả lời
(B)
CuS
5
What is the PH of 0.00 1 moldm\(^3\) solution of the sodium hydroxide
Trả lời
(D)
11
6
The type of bonding in [Cu(NH\(_3\))\(^4\)]\(^{2+}\) is
Trả lời
(A)
coordinate
7
Which of the following is an example of a chemical change?
Trả lời
(B)
rusting of iron
8
To what temperature must a gas at 273k be heated in order to double both its volume and pressure?
Trả lời
(D)
1092K
9
According to the Kinetic Theory an increase in temperature causes the kinetic energy of particles to
Trả lời
(B)
increase
10
An element used in the production of matches is
Trả lời
(D)
sulphur
11
Which of the following gases may not be dried with concentrated sulphuric acid?
Trả lời
(B)
NH\(_3\)
12
The Consecutive members of an alkane homologous series differ by
Trả lời
(B)
CH\(_2\)
13
A correct electrochemical series can be obtained from Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging
Trả lời
(A)
Al and Mg
14
A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that
Trả lời
(A)
collisions are perfectly elastic
15
On which of the following is the solubility of a gaseous substance dependent?
I. Nature of solvent
II. Nature of solute
III. Temperature
IV. Pressure
Trả lời
(D)
III and IV only
16
Which of the following statements is correct about the periodic table?
Trả lời
(B)
The valence electrons of the elements in the same period increase progressively across the period
17
The periodic classification is an arrangement of the elements
Trả lời
(D)
atomic numbers
18
If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litres of water and the resulting solution mixed thoroughly, the resulting sulphuric acid concentration will be
Trả lời
(C)
0.2M
19
In the shown experiment (Fig. 1) the litmus paper will initially
Trả lời
(D)
turn blue
20
The boiling of fat and aqueous caustic soda is referred to as
Trả lời
(D)
saponification
21
Which of the following pairs of substances will react further with oxygen to form a higher oxide?
Trả lời
(D)
SO\(_2\) and NO
22
In the preparation of oxygen by heating KCIO\(_3\) , in the presence of MnO\(_2\) only moderate heat is needed because the catalyst acts by \(_2\)
Trả lời
(C)
increasing the rate of the reaction
23
Methanoic acid mixes with water in all proportions and has about the same boiling point as water. Which of the following methods would you adopt to obtain pure water from a mixture of Sand, water and methanoic acid?
Trả lời
(A)
Extractive distillation
24
A quantity of electricity liberates 3.6g of Silver from its salt. What mass of aluminium Will be liberated from its salt by the same quantity of electricity? [Al = 27, Ag = 108].
Trả lời
(D)
0.3g
25
Suitable reagents for the laboratory preparation of nitrogen are
Trả lời
(A)
sodium dioxonitrate(III) and ammonium chloride
26
The number of electrons in the valence shell of an element of atomic number 14 is?
Trả lời
(D)
4
27
What volume of oxygen will remain after reacting 8cm\(^3\) of hydrogen gas with 20cm\(^3\) of oxygen gas?
Trả lời
(D)
16cm\(^3\)
28
If one of the following oxides is heated with hydrogen or carbon using a bunsen burner. it is not reduced to the metal, Which one is it?
Trả lời
(B)
Magnesium oxide
29
The lUPAC name for
Trả lời
(C)
2-methylbutane
30
An aqueous solution of a metal salt, M. gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia Therefore the cation in M is
Trả lời
(A)
Zn
31
What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution? [Na = 23, O =16, H = 1]
Trả lời
(B)
0.50 moldm\(^{-3}\)
32
How many atoms are present in 6.0g of magnesium? [Mg = 24, N.A = 6.02 x 10 \(^{23}\)mol]
Trả lời
(C)
1.51 x 10\(^{23}\)
33
The radio isotope used in industrial radiography for the rapid checking of faults in welds and casting is?
Trả lời
(C)
cobalt-60
34
Beryllium and Aluminium have similar properties because they
Trả lời
(D)
are positioned diagonally to each other
35
mE + nF -----> pG + qH
In the equation shown, the equilibrium constant is given by?
Trả lời
(C)
\(\frac{[G]^p[H]^q}{[E]^m[F]^n}\)
36
(I). 3CuO(s) + 2NH3(g) -----> 3Cu(s) + 3H2O(l) + N2(g)
(II). 2NH3(g) + 3Cl2(g) -----> 6HCl(g) + N2(g)
(III). 4NH3(g) + 3O2(g) -----> 6H2O(l) + N2(g)
The reactions represented by the equations above demonstrate the
Trả lời
(C)
reducing properties of ammonia
37
The salt that reacts with dilute hydrochloric acid to produce a pungent smelling gas which decolourizes acidified purple potassium tetraoxomanganate (VII) solution is
Trả lời
(B)
Na\(_2\)SO\(_3\)
38
The refreshing and characteristic taste of soda water and other soft drinks is as a result of the presence of
Trả lời
(A)
carbon(IV)oxide
39
Which of the following are mixtures?
I. Petroleum
II. Rubber latex
III. Vulcanizer's solution
IV. Carbon sulphide
Trả lời
(A)
I, II and III
40
A balanced chemical equation obeys the law of
Trả lời
(A)
conservation of mass
41
When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;
Trả lời
(D)
nitrogen and the rare gases
42
In the laboratory preparation of oxygen, the gas cannot be collected by downward displacement of air because
Trả lời
(B)
the density of air is nearly the same as that of oxygen
43
2KClO\(_3\)(s) → 2KCl(s) + 3O\(_2\)(g)
The importance of the catalyst in the reaction above is that
Trả lời
(D)
the reaction takes place more rapidly at a lower temperature
44
Which of the following is used to power steam engines?
Trả lời
(B)
coal
45
In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?
Trả lời
(D)
50cm\(^3\)
46
To what volume must 300cm\(^3\) of 0.60M sodium hydroxide solution be diluted to give a 0.40M solution?
Trả lời
(A)
450cm\(^3\)
47
Diamond is a bad conductor of electricity because its bonding electrons are used in
Trả lời
(B)
covalent bond formation
48
The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;
Trả lời
(C)
esterification
49
The constituent common to duralumin and alnico is
Trả lời
(C)
Al
50
The solubility of the solids that dissolves in a given solvent with the liberation of heat will
Trả lời
(B)
decrease with an increase in temperature
51
What mass of Cu would be produced by the cathodic reduction of Cu\(^{2+}\) when 1.60A of current passes through a solution of CuSO\(_4\) for 1 hour. (F=96500Cmol\(^{-1}\) , Cu=64)
Trả lời
(C)
1.91g
52
Calculate the pH of 0.05 moldm\(^{-3}\) H\(_2\)SO\(_4\)
Trả lời
(C)
1.00
53
The choice of method for extracting a metal from its ores depends on the
Trả lời
(B)
position of the metal in the electrochemical series
54
Which of the following produces relatively few ions in solution?
Trả lời
(D)
AI(OH)\(_3\)
55
The figure above shows the electrolysis of molten sodium chloride. Z is the
Trả lời
(A)
anode where the Cl\(^-\) ions are oxidized
56
The knowledge of half-life can be used to
Trả lời
(B)
Detect an element
57
An element X forms the following compounds with chlorine; XCl\(_4\), XCl\(_3\), XCl\(_2\). This illustrates the
Trả lời
(A)
law of multiple proportions
58
The hydrogen ion concentration of a sample of orange juice is 2.0 X 10\(^{-11}\)moldm\(^{-3}\). What is its p\(^{OH}\)? [log102 = 0.3010]
Trả lời
(A)
3.30
59
2SO\(_2\) \(_{(g) }\)+ O\(_2\) \(_{(g) }\) ↔ 2SO\(_3\)\(_{(g) }\) ΔH = -395.7kJmol\(^{-1}\)
In the equation, an increase in temperature will shift the equilibrium position to the
Trả lời
(A)
left and equilibrium constant decreases
60
The end products of burning a candle in the atmosphere are water and
Trả lời
(C)
carbon (IV) oxide
61
The collision theory explains reaction rates in terms of
Trả lời
(B)
frequency of collision of the reactants
62
The presence of ammonia gas in a desiccator can exclusively be removed by
Trả lời
(D)
concentrated tetraoxosulphate (VI) acid
63
Aluminium does not react with either dilute or concentrated trioxonitrate (V) acid because
Trả lời
(D)
an insoluble oxide is formed on its surface which renders it passive
64
Which of these sources of water may likely contain the least concentration of Ca\(^{2+}\) and Mg\(^{2+}\)?
Trả lời
(C)
Tap water
65
The conductivity of an acid solution depends on the
Trả lời
(A)
amount of ions present and their mobilities
66
Which of the following metals cannot replace hydrogen from water or steam?
Trả lời
(D)
Copper
67
Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,
Trả lời
(D)
Q will form an electrovalent bond with S
68
During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment
Trả lời
(D)
the litmus turns red and oxygen is evolved
69
The derivative of benzene that can be used in making explosives is
Trả lời
(D)
toluene
70
In electrovalency, the oxidation number of the participating metal is always
Trả lời
(B)
increasing
71
The ionic radii of metals are usually
Trả lời
(D)
less than their atomic radii
72
Calculate the percentage composition of oxygen in calcium trioxocarbonate(IV) [Ca=40, C=12, O=16]
Trả lời
(B)
48
73
Which of these alloys contains copper?
Trả lời
(D)
bronze
74
If the molecular mass of tetraoxosulphate (VI) acid is 98, calculate its vapour density.
Trả lời
(B)
49
75
Sieving is a technique used to separate mixtures containing solid particles of
Trả lời
(C)
different sizes
76
3H\(_{2(g)}\)+ N\(_{2(g)}\)⇔ 2NH\(_{3(g)}\) ; H= -ve
In the reaction above, lowering of temperature will
Trả lời
(C)
favour the forward reaction
77
The situation obtained when a perfect gas expands into a vacuum is
Trả lời
(D)
ΔH is zero and T Δ S is positive
78
The general formula of alkanones is
Trả lời
(B)
R\(_2\)CO
79
The alkanoic acid found in human sweat is
Trả lời
(B)
CH\(_3\)—CH\(_2\)—COOH
80
The elements in the periodic table are listed in order of increasing
Trả lời
(A)
relative atomic number
81
H\(_2\) S\(_{(g)}\) + Cl\(_{2(g)}\) → 2HCl\(_{(g)}\) + S\(_{(g)}\) In the reaction above, the substance that is reduced is
Trả lời
(D)
Cl\(_2\)
82
Which of the compounds is composed of Al, Si, O and H?
Trả lời
(C)
Clay
83
When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as
Trả lời
(C)
cracking
84
In the removal of water hardness, permutit is regenerated with a strong solution of
Trả lời
(D)
NaCl
85
A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by
