The number of orbitals in a p-sub level of an atom is
คำตอบ
(B)
3
2
Which of the following electron configurations represents that of an atom in its ground state?
คำตอบ
(D)
1s22s22p63s0
3
Which of the following ions has an electron configuration different from the other?
คำตอบ
(A)
17CI-
4
The atomic radii of metals are usually
คำตอบ
(A)
greater than their ionic radii
5
Two elements, X and Y are in the same group on the periodic table because they both have the same
คำตอบ
(B)
number of valence electrons
6
The d-block elements are paramagnetic because they
คำตอบ
(B)
contain unpaired electrons in the partially filled 3d-orbital
7
Which of the following statements about a radioactive substance is/are correct? l. lt emits radiation continuously and spontaneously. ll. The emitted radiations are affected by temperature and pressure III. The radiation can penetrate opaque matter
คำตอบ
(C)
l and lll only
8
Which of the following elements is a metalloid?
คำตอบ
(C)
Silicon
9
Which of the following halogens is liquid at room temperature?
คำตอบ
(D)
Bromine
10
The shape of a graphite crystal is
คำตอบ
(C)
hexagonal
11
The complex compound formed by the combination of two elements with a large electronegativity difference is likely to be
คำตอบ
(D)
ionic
12
The complex compound formed when aluminum dissolves in aqueous sodium hydroxide is
คำตอบ
(B)
NaAl(OH)4
13
The vapour pressure of a liquid depends on l. temperature. ll. rate of condensation. III. cohesive forces holding the particles together
คำตอบ
(C)
l and lll only
14
MgO does not readily dissolve in water because
คำตอบ
(D)
its lattice energy is higher than its hydration energy
15
Consider the following reaction equation: CaCO\(_{3(s)}\) + 2HCI\(_{(aq)}\) → CaCl\(_{2(aq)}\) + H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\). What mass of CaCI\(_2\) would be obtained when 25.0g of CaCO\(_{3(s)}\) is reacted with excess HCI\(_{(aq)}\)? [CaCO\(_3 = 100; CaCI\(_2\) = 111]
คำตอบ
(D)
27.8 g
16
The number of sulphur atoms in 3.20g of SO\(_{2(g)}\) is [O = 16.0;S = 32.0; Avogadro constant = 6.02 x 10\(^{23}\)]
คำตอบ
(A)
3.01 x 1022
17
Consider the reaction represented by the following equation: xCH\(_3\)OH + yO\(_2\) → 2CO\(_2\) + zH\(_2\)O. The values of x,y and z respectively, are
คำตอบ
(A)
2,3 and 4
18
The formula of mercury (l) dioxonitrate (III) is
คำตอบ
(C)
Hg2(NO2)2
19
A sample of a gas may be identified as chlorine if it turns
คำตอบ
(D)
starch iodide paper blue-black
20
A metal M forms two types of chlorine, MCl\(_2\) and MCl\(_3\) which of the following laws best explains the relationship between the chlorides? Law of
คำตอบ
(C)
multiple proportion
21
Which of the following metals would readily displace hydrogen from steam?
คำตอบ
(C)
Magnesium
22
The volume occupied by 0.4 g of hydrogen gas at s.t.p. is [H = 1. 00; Molar volume at s.t.p. = 22.4 dm3]
คำตอบ
(B)
4.48dm3
23
When a substance changes directly from the solid state to the gaseous state without forming a liquid, the substance is said to
คำตอบ
(C)
sublime
24
At ordinary temperature H\(_2\)O is a liquid while H\(_2\)S is a gas. This is because H\(_2\)O has
คำตอบ
(B)
strong hydrogen bonds holding its molecules together
25
The postulate that molecules are in constant random motion best explains why liquids
คำตอบ
(A)
can undergo solidification
26
Which of the following gases has the lowest rate of diffusion under the same condition? [H = 1.00; He = 4. 00; O = 16.0; CI = 35.5]
คำตอบ
(A)
CI2
27
The energy evolved when magnesium burns in air is in the form of
คำตอบ
(C)
light and heat
28
A substance L reacts with NH\(_4\)NO\(_{3(aq)}\) to generate ammonia gas. L is likely to be
คำตอบ
(B)
NaOH
29
On heating, the following trioxocarbonate (IV) salts decompose to give solid residue except
คำตอบ
(A)
ammonium trioxocarbonate (IV)
30
Which of the following pH values indicates that a solution is a strong base?
คำตอบ
(D)
13
31
The hydrolysis of NH\(_4\)CI gives
คำตอบ
(A)
an acidic solution
32
A spot of oil paint on a shirt can best be removed using?
คำตอบ
(C)
kerosine
33
Consider the reaction represented by the following equation: CuO\(_{(s)}\) + H\(_2\)SO\(_{4(aq)}\) → CuSO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\). Which of the following factors will not affect the rate of the reaction?
คำตอบ
(D)
Pressure of reaction system
34
Which of the following devices function on redox reaction? l. Dry cell ll. Car battery III. Electric generator
คำตอบ
(C)
l and ll only
35
The oxidation number of Fe in [Fe(CN)\(_6\)]\(^{3-}\) is
คำตอบ
(A)
+3
36
Consider the following reaction equation: C\(_{16}\)H\(_{34}\) → C\(_5\)H\(_{12}\) + C\(_{11}\)H\(_{22}\). The process represented by the equation is
คำตอบ
(A)
cracking
37
Which of the following substances would not produce ethanol when fermented?
คำตอบ
(D)
Vinegar
38
An alkanol can be prepared by the reaction of an alkene with
คำตอบ
(A)
concentrated tetraoxosulphate (VI) acid
39
A tertiary alkanol has a molecular formula C\(_4\)H\(_{10}\)O. What is the structural formula of the compound?
คำตอบ
(C)
(CH3)3COH
40
Which of the following industrial processes depends on the action of enzymes?
