A mixture of sugar and sulphur can be separated by?
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(C)
dissolution in water, filtration and evaporation
2
Which of the following is a physical change?
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(A)
Freezing ice cream
3
The percentage of water of crystallization in ZnSO\(_4\).7H\(_2\)O is?
[Zn = 65, S = 32, O = 16, H = 1]
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(B)
44%
4
0.0075 mole of calcium trioxocarbonate (IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p is?
[Molar volume of a gas at s.t.p = 22.4 dm3]
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(B)
168cm3
5
A gas exerts pressure on its container because?
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(A)
the molecules of a gas collide with the walls of the container
6
The basic assumption in the kinetic theory of gases that the collisions of the gaseous molecules are perfectly elastic implies that the?
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(C)
gaseous molecules will continue their motion indefinitely
7
If an atom is represented as \( _{11}^{23}X \), which of the following deduction is correct?
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(D)
it is an alkali metal
8
Cathode rays causes an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays?
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(D)
travel in straight lines
9
Which quantum number divides shells into orbitals?
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(B)
Arzimuthal
10
The type of bonding in \({Cu(NH_3)_4}^2\)+ is?
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(A)
coordinate covalent
11
The mixture of gases used in a photographer's flash tube is?
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(B)
krypton and xenon
12
When sodium trioxocarbonate (IV) decahydrate loses its water of crystallization to the atmosphere, the process is?
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(B)
efflorescence
13
Water can be obtained as the only product during the?
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(C)
combustion of hydrogen
14
If 10.5g of lead (II) trioxonitrate (V) is dissolved in 20cm3 of distilled water at 18oC, the solubility of the solute in mol dm-3 is
[Pb = 207, N = 14, O = 16]
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(A)
1.60
15
For a given solute, the concentration of its saturated solution in different solvents are
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(B)
different at the same temperature
16
The major source of oxides of nitrogen is from the burning of
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(C)
fuel
17
The acid used in electrolysis of water is dilute?
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(C)
H2SO4
18
What volume of 1.5M solution of KOH would contain 0.045 moles
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(B)
30.00 cm3
19
The salt formed from a reaction between citric acid and sodium hydroxide in solution will be?
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(B)
basic
20
The colour changes observed when testing for reducing agents using acidified potassium heptaoxodichromate (VI) solution is?
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(B)
orange to green
21
The oxidation state of Cr in K\(_2\)Cr\(_2\)O\(_7\) is?
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(B)
+6
22
Which of the following metals is purified commercially by electrolysis?
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(D)
Cu
23
What current will deposit 3.25g of zinc in 2hrs?
[Zn = 65, F = 96500 mol-]
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(C)
1.34A
24
C(s) + H2O(g) → H2(g) + CO2(g)
ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is?
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(C)
feasible
25
Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth - to - mouth to each other at room temperature. The entropy in the mixture of gases is likely to?
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(B)
increase
26
In the diagram above, which of the curves represents the evolution of oxygen with time in the equation 2KClO3(s) → 2KCl(s) + 3O2(g)?
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(D)
R
27
A catalyst increase the rate of a chemical reaction by providing a path that?
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(C)
lowers the activation energy
28
CuO(s) + H\(_2\)(g) ↔ Cu(s) + H\(_2\)O(g)
What is the effect of increasing the pressure on the equilibrium reaction above?
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(C)
There is no effect
29
The equilibrium of an endothermic reaction which proceeds with an increase in volume can be shifted in the reverse direction by
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(C)
decreasing the temperature and increasing the pressure
30
The oxidation of ammonia in excess air produces?
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(A)
NO
31
Hydrogen sulphide gas can act as?
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(D)
a precipitating agent
32
The gasification of coke is used for the manufacturing of?
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(C)
synthetic gas
33
The gas that is most useful in protecting humans against solar radiation is?
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(B)
ozone
34
Which of the following allotrope of carbon is a constituent of a lead pencil?
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(A)
Graphite
35
which of the following metals will show the highest metallic character?
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(C)
Barium
36
Copper metal dissolves in concentrated trioxonitrate (V) acid with the resultant evolution of?
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(C)
NO2
37
The type of iron that is best suited for welding, making nails, chains and iron rods is?
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(B)
wrought iron
38
In the electrolytic extraction of aluminum, the function of the molten cryolite is to
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(B)
lower the melting point of aluminium oxide
39
One of the products of the thermal decomposition of sodium trioxonitrate (V) is?
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(C)
sodium dioxonitrate (III)
40
A cracking process in petroleum refining can be represented by
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(C)
heptane to propene and butane
41
Which of the following molecules has two other positional isomers?
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(D)
CH2CHBrCH2Br
42
Which of the following class of compounds can exist as dipolar ions in solution?
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(D)
Amino acids
43
Lucas reagent is used to test for?
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(C)
alkanols
44
A compound commonly used for sterilization and preservation of specimens and food is
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(A)
ethanol
45
An organic compound reacted with bromine water to give a colourless solution. The compound is probably an?
