What volume of oxygen is produced from the decomposition of 2 mole of KCIO3 at s.t.p?
[Molar volume of a gas at s.t.p = 22.4 dm3]
Trả lời
(D)
67.2 dm3
2
Which of the following is physical change?
Trả lời
(B)
Freezing ice cream
3
What is the percentage by mass of oxygen in Al2(SO4)3. 2H2O?
[Al = 27, S = 32, H = 1, O = 16]
Trả lời
(D)
59.25%
4
The filter in the cigarette reduces the nicotine content by
Trả lời
(B)
Adsorption
5
3Cu + pHNO3 →3Cu(NO)2 + 4H2 O + xNO
In the equation above, the values of p and x respectively are
Trả lời
(D)
8 and 2
6
Neutral atoms of neon with atomic number 10 have the same number of electron as
Trả lời
(D)
Mg2+
7
The noble gases owe their inactivity to
Trả lời
(A)
Octet configuration
8
According to the kinetic theory, an increase in temperature causes the kinetic energy of particles to
Trả lời
(B)
Increase
9
I. H = 1S\(^1\) II. N = 1S\(^2\) 2S\(^2\)2P\(^3\) III. O = 1S\(^2\) 2S\(^2\) 2P\(^4\) IV. Zn = 1S\(^2\) 2S\(^2\) 2P\(^6\) 3S\(^2\) 3P\(^6\) 4S\(^2\) 3d\(^{10}\)
From the above, which of the following pairs is like to be paramagnetic?
Trả lời
(B)
I and III
10
A gas exerts pressure on its container because
Trả lời
(D)
the molecules of a gas collide with the walls of the container
11
When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes
Trả lời
(A)
negatively charged
12
The weakest attractive force that can be observed between two molecules is
Trả lời
(D)
van der Waals
13
A consequence of global warming is?
Trả lời
(D)
flooding
14
Which of the following ions is acidic?
Trả lời
(D)
H3O+
15
The structural component that makes detergent dissolve more quickly in water than soap is
Trả lời
(A)
-SO3- Na+
16
A liquid that will dissolve fat is?
Trả lời
(C)
Kerosene
17
What mass of K2CrO4 is required to prepare 250cm3 of 0.020 mol dm3 solution?
[K2CrO4 = 194.2g mol-1]
Trả lời
(A)
0.97g
18
Farmlands affected by crude-oil spillage can be decontaminated by
Trả lời
(B)
Using aerobic bacteria
19
When 10g of sodium hydroxide is dissolved in 1000cm\(^3\) of water, the sodium formed is approximately
[Na = 23, H = 1, O = 16]
Trả lời
(C)
0.25 mol dm-3
20
A change in temperature of a saturated solution disturb the equilibrium between the
Trả lời
(C)
Dissolved solute and undissolved solute
21
If an equilibrium reaction has ΔH > 0, the reaction will proceed favourably in the forward direction at
Trả lời
(A)
High temperature
22
The commonest feature of reactions at the anode is that
Trả lời
(B)
oxidation is involved
23
Which of the following will change when a catalyst is added to a chemical reaction?
Trả lời
(A)
The activation energy
24
If y is an oxidizing agent that reacts with a reducing agent, Z, which of the following is correct?
Trả lời
(B)
Y becomes reduced
25
When at equilibrium, which of the reactions below will shift to the right if the pressure is increased and the temperature is kept constant?
Trả lời
(C)
2H2(g) + O2(g) ↔ 2H2O(g)
26
In the electrolysis of a concentrated solution of sodium chloride using electrodes, which of the following ions are discharged at the cathode and anode respectively?
Trả lời
(D)
H+ and Cl-
27
CO(g) + H2O(g) → CO2(g) + H2(g)
From the reaction above, calculate the standard enthalpies of formation if CO2(g), H2O(g) and CO(g) in kJ mol-1 are -394, -242, and -110 respectively.
Trả lời
(B)
-42 kJ mol-1
28
When sugar is dissolved in tea, the reaction is always accomplished by
Trả lời
(A)
positive change in entropy
29
Which of the following is an electrolyte?
Trả lời
(B)
Sodium acetate solution
30
Chlorine gas is prepared in the laboratory by
Trả lời
(A)
adding concentrated hydrochloric acid to solid manganese (IV) oxide
31
Metals of the first transition series have special properties which are different from those of groups I and II elements because they have partially filled
Trả lời
(C)
d orbitals
32
Hydrogen can be displaced from a hot alkaline solution by?
Trả lời
(D)
Sn
33
Which of the following statements is true of sulphur (IV) oxide?
Trả lời
(C)
It is an acid hydride
34
The salt that will form a precipitate soluble in excess ammonia solution is
Trả lời
(B)
Cu(NO3)2
35
The metal that liberates hydrogen from cold water in bubbles only is?
Trả lời
(C)
Ca
36
Chlorine gas turns a damp starch-iodide paper
Trả lời
(D)
dark blue
37
The modern process of manufacturing steel for iron is by
Trả lời
(C)
blast reduction
38
Ethene reacts with hydrogen bromide to give
Trả lời
(B)
CH3CH2Br
39
How many isomers does pentane have?
Trả lời
(D)
3
40
The leachate of a certain plant ash is used in local soap making because it contains
Trả lời
(C)
potassium hydroxide
41
The formula for ethyl butanoate is
Trả lời
(A)
C3H7COOC2H5
42
The type of reaction that is peculiar to benzene is?
Trả lời
(D)
substitution
43
Ethanol reacts with excess acidified K\(_2\)Cr\(_2\)O\(_7\) to produce
Trả lời
(D)
ethanoic acid
44
A compound contains 40.0% carbon 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180, find the molecular formula.
[H = 1, C = 12, O = 16]
Trả lời
(C)
C6H12O6
45
The process by which atoms are rearranged into different molecular structure in the petroleum refining process is referred to as
