What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution?
[Na = 23, O = 16, H = 1]
คำตอบ
(B)
0.50 mol dm-3
2
Which of the following properties is NOT peculiar to matter?
คำตอบ
(D)
Random motion of particles increases from gas to solid
3
From the diagram above, an ideal can be represented by
คำตอบ
(B)
N
4
Which of the following questions is correct about the periodic table?
คำตอบ
(B)
The valence electrons of the elements increase progressively across the period
5
The relative atomic mass of a naturally occurring lithium consisting of 90% \(^7 _3\)Li and \(^6 _3\)10% Li is
คำตอบ
(A)
6.9
6
An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contain is
คำตอบ
(B)
15
7
The molecular lattice of iodine is held together by
คำตอบ
(D)
van der Waal's forces
8
The arrangement of particles in crystal lattices can be studied using
คำตอบ
(A)
X - rays
9
From the diagram above, find the amount of solute deposited when 200 cm\(^3\) of the solution is cooled from 55°C to 40°C.
คำตอบ
(B)
0.20mole
10
The importance of sodium aluminate (III) in the treatment of water is to
คำตอบ
(A)
cause coagulation
11
What type of bond exits between an element X with atomic number 12 and Y with atomic number 17?
คำตอบ
(A)
Electrovalent
12
Hardness of water is mainly due to the presence of
คำตอบ
(B)
calcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)
13
A suitable solvent for iodine and naphthalene is
คำตอบ
(D)
benzene
14
Which of the following noble gases is commonly found in the atmosphere?
คำตอบ
(D)
Argon
15
N2O4(g) ↔ 2NO2(g) ΔH = +ve
In the reaction above, an increase in temperature will
คำตอบ
(A)
increase the value of the equilibrium constant
16
CH3COOH(aq) + OH-(aq) ↔ CH3COO-(aq) + H2O(l)
In the reaction above ,CH3COO-(aq) is
คำตอบ
(A)
conjugate base
17
How many cations will be produced from a solution of potassium aluminium tetraoxosulphate (VI)?
คำตอบ
(D)
2
18
Which of the following is NOT an alkali?
คำตอบ
(B)
Mg(OH)2
19
An effect of thermal pollution on water bodies is that the
คำตอบ
(D)
level of oxygen reduces
20
Which of the following is a deliquescent compound?
คำตอบ
(B)
CaCl2
21
A chemical reaction which the hydration energy is greater than the lattice energy is referred to as
คำตอบ
(C)
an exothermic reaction
22
The function of zinc electrode in a galvanic cells is that it
คำตอบ
(C)
production of electons
23
CH4(g) + Cl2(g) → CH3 Cl(s) + HCl(g)
The major factor that influence the rate of the reaction above is
คำตอบ
(D)
light
24
The condition required for corrosion to take place is the presence of
คำตอบ
(D)
water and oxygen
25
The diagram above best illustrates the effect of decrease in
คำตอบ
(A)
concentration
26
MnO-4(aq) + Y + 5Fe2+(aq) → Mn2+(aq) + 5Fe2+(aq) + 4H2O(l)
In the equation above, Y is
คำตอบ
(D)
8H+(aq)
27
Given that M is the mass of a substance deposited during electrolysis and Q is the quantity of electricity consumed, then Faraday's first law can be written as
[Electrochemical equivalent]
คำตอบ
(B)
M = EQ
28
The impurities formed during the laboratory preparation of chlorine gas are removed by
คำตอบ
(C)
H2SO4
29
The effect of the presence of impurities such as carbon and sulphur on iron is that they
คำตอบ
(D)
lower its melting point
30
A few drops of concentrated HNO\(_3\) is added to an unknown solution and boiled for a while. If this produces a brown solution, the cation present is likely to be
คำตอบ
(C)
Fe3+
31
The bleaching action of chlorine gas is effective due to the presence of
คำตอบ
(B)
water
32
In the laboratory preparation of oxygen, dried oxygen is usually collected over
คำตอบ
(B)
mercury
33
The property of concentrated H2SO4 that makes it suitable for preparing HNO3 is its
คำตอบ
(A)
boiling point
34
Bronze is preferred to copper in the making of medals because it
คำตอบ
(A)
is stronger
35
The constituents of baking powder that makes the dough to rise is
คำตอบ
(A)
NaHCO3
36
The ability of carbon to form long chains is referred to as
คำตอบ
(C)
catenation
37
Which of the following compounds will undergo polymerization reaction?
คำตอบ
(A)
C2H4
38
An organic compound has an empirical formula CH2O and vapour density of 45.
What is the molecular formula?
[C = 12, H = 1, O = 16]
คำตอบ
(C)
C3H6O3
39
At 25o and zymase as catalyst,
C6H126 → 2C2H5OH + 2CO2 + energy
The reaction above represented by the equation above is useful in the production of
คำตอบ
(D)
ethanol
40
The number of isomers that can be obtained from C\(_4\)H\(_{10}\) is
คำตอบ
(D)
2
41
The functional groups present in the compound above are
คำตอบ
(D)
hydroxyl and halo-group
42
Two organic compounds K and L were treated with a few drops of Fehling's solutions respectively . K formed a brick-red precipitate while L, remains unaffected. The compound K is an
คำตอบ
(C)
alkanal
43
Which of the following statements is true about 2-methylpropane and butane
คำตอบ
(D)
They have the same chemical properties
44
with conc H2SO4 as catalyst
CH3COOH + C2H5OH → CH3COOC2H5 + H2O
