25cm\(^3\) of a gas X contains Z molecules at 15\(^0\)C and 75 mmHg. How many molecules will 25cm\(^3\) of another gas Y contain at the same temperature and pressure?
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(C)
Z
2
What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?
[H = 1, O = 16]
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(C)
72.0g
3
A particle that contains 9 protons, 10 neutrons and 10 electrons is a
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(A)
negative ion
4
Cancerous growths are cured by exposure to
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(A)
γ - rays
5
An oxide XO\(_2\) has a vapour density of 32. What is the atomic mass of X?
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(A)
32
6
Millikan's contributions to the development of atomic theory is the determination of
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(A)
charge on electron
7
Four elements W, X, Y and Z have atomic number 2,6,16 and 20 respectively. Which of these elements is a metal?
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(C)
Z
8
An element X with relative atomic mass 16.2 contains two isotopes \(^{16}_{8}\)X with relative abundance of 90% and \(^{m}_{8}\)X with relative abundance of 10%. The value of m is
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(B)
18
9
Which of the following statements is correct about the average kinetic energy of the molecules of a gas?
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(C)
It increase with increase in temperature
10
The pollution from petroleum spillage in rivers and lakes can best be dispersed by
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(B)
Passing of ships through the area
11
Deliquescent substances are used for
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(D)
Drying
12
Pure solvents are obtained by
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(A)
Distillation
13
What is the decrease in volume of air when pyrogallol is shaken with 30.00cm\(^3\) of air ?
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(B)
6.30cm3
14
Environmental pollution is worsened by the release from automobile exhausts of?
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(C)
Smoke
15
The chemical used for coagulation in water purification is
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(A)
Aluminium tetraoxosulphate (VI)
16
Phosphorus is stored under water to prevent it from
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(D)
Catching fire
17
In which of the following reactions does reduction takes place
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(D)
2H+ + 2e- → H2
18
P(g) + Q(g) ↔ 3R(s) + S(g) ΔH is negative
Which of the following will increase the yield of R?
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(C)
Removing some S
19
A metal M displaces zinc from zinc chloride solution. This shows that
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(C)
M is more electropositive than zinc
20
Which of the following best explains the increase in the rate of a chemical reaction as the temperature rises?
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(D)
The collision frequency of the molecules increase
21
What current in amperes will deposit 2.7g of aluminium in 2 hours?
[Al = 27, F = 96 500 C mol-1]
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(C)
4
22
Ethanoic acid is
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(C)
monobasic
23
C(s) + 2S(g) → CS\(_2\)(g)
ΔH = +89 kJ mol-1
The chemical equation above implies that
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(D)
89 kJ of energy is absorbed
24
2SO\(_2\)(g) + O\(_2\)(g) ↔ 2SO\(_3\)(g)
ΔH = -189 kJ mol-1
The equilibrium constant for the reaction above is increased by?
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(A)
decreasing the temperature of the system
25
3Cu(s) + 8HNO\(_3\)(aq) → 3Cu(NO\(_3\))\(_2\)(aq) + 4H\(_2\)O(l) + 2NO(g)
In the equation above, copper is
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(D)
a reducing agent
26
When ΔH is negative, a reaction is said to be
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(C)
exothermic
27
As the concentration of an electrolyte reduces, the conductivity
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(B)
decreases
28
In which of the following reactions has the oxidation number of nitrogen increased?
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(B)
2NO(g) + O2(g) → 2NO2(g)
29
NH\(_3\)\(_{(g)}\) + HCl\(_{(g)}\) → NH\(_4\)Cl\(_{(s)}\)
The entropy change in the system above is
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(A)
negative
30
Fermentation is the
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(B)
conversion of sugar to alcohol in the presence of yeast
31
The general formula for the alkanals is
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(D)
RCHO
32
The main impurity in iron ore during the extraction of iron is
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(A)
Silicon (IV) oxide
33
During the vulcanization of rubber, sulphur is added to
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(C)
Bind rubber molecules together
34
Catalytic hydrogenation of benzene produces
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(C)
Cyclohexane
35
A trihydric alkanol is
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(A)
Glycerol
36
When chlorine Is passed into water and the resulting solution exposed to sunlight, the product formed are
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(D)
Hydrochloric acid and oxygen
37
Proteins in acid solution undergo
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(D)
Hydrolysis
38
A characteristic reaction of the compounds with the general formula C\(_n\)H\(_{2n}\) is
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(B)
Polymerization
39
The pair of organic compounds that are isomers is
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(D)
But-1-ene and but-2-ene
40
A burning candle produces water and
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(B)
Carbon (IV) oxide
41
The gas that can best be collected by downward displacement of air is
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(C)
Ammonia
42
Which of the following metals burn with brick red flame?
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(B)
Ca
43
Which of the following represent hybridization in ethyne?
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(D)
Sp
44
\(C_{12}H_{22}O_{11(s)} + H_2SO_{4(aq)} → 12C(s) + 11H_2O(l) + H_2SO_{4(aq)}\)
In the reaction above, tetraoxosulphate (VI) acid function as
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(A)
A dehydrating agent
45
When sodium reacts with water, the resulting solution is
