Which of the following species determines the chemical properties of an atom?
คำตอบ
(A)
Electron
2
The following glasswares are used to measure the volume of liquids EXCEPT
คำตอบ
(C)
test tube
3
Pauli exclusion principle is related to
คำตอบ
(D)
quantum numbers of electrons
4
The species with no electron in the 3d-orbital is
คำตอบ
(B)
\(Sc^{3+}\)
5
The seperation of Nitrogen from oxygen using fractional distillation of air is possible because
คำตอบ
(C)
of the difference in their boiling points
6
The purity of a solid sample can best be determined by its
คำตอบ
(B)
melting point
7
The mass of one mole of \((NH_{4})_{2}CO_{3}\) is [O=16.0, N=14.0, C=12.0, H=1.0]
คำตอบ
(D)
96.0g
8
Atomic orbital is
คำตอบ
(B)
a region around the nucleus where electrons are most likely to be found
9
The property of elements which increases down a group of the periodic table is
คำตอบ
(C)
ionic radius
10
The reason for the decrease in the atomic size of elements across a period is that
คำตอบ
(A)
nuclear charge increases while the outermost electrons are drawn closer to the nucleus
11
The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is
คำตอบ
(D)
+5
12
Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements?
คำตอบ
(B)
Cl, P, Al, Na
13
Which of the following metals has the strongest metallic bond?
คำตอบ
(A)
\(_{13}Al\)
14
Which of the following substances does not have van der Waals' forces?
คำตอบ
(A)
Copper
15
The oxidation number of X in \(XO_{4}^{3-}\) is
คำตอบ
(D)
+5
16
The ionization energy is affected by the following factors except
คำตอบ
(C)
ability to attract shared electron(s)
17
Which of the following statements is correct?
คำตอบ
(D)
Ionic compounds in solution would conduct electricity
18
The bond angle in tetrahedral molecules such as tetrachloromethane is
คำตอบ
(B)
109.5°
19
The properties of a good primary standard include the following except
คำตอบ
(B)
low molecular mass
20
The use of diamond in abrasives is due to its
คำตอบ
(B)
hardness
21
Which of the following statements about endothermic reaction is correct?
คำตอบ
(D)
Heat energy is absorbed
22
A 0.1\(moldm^{-3}\) solution of sodium hydroxide was diluted with distilled water to 0.001\(moldm^{-3}\). What is the dilution factor?
คำตอบ
(B)
100.00
23
Graphite and Diamond are similar in that they
คำตอบ
(C)
form carbon(IV) oxide on combustion
24
In a saturated solution at a given temperature, the undissolved solutes are in equilibrium with
คำตอบ
(B)
dissolved solute particles
25
The number of atoms present in 2.5moles of a triatomic gas is equivalent to [1mole = \(6.02\times 10^{23}\)]
คำตอบ
(C)
\(1.5\times 10^{24}\)
26
When Magnesium reacts with oxygen, heat is
คำตอบ
(C)
evolved and the reaction is exothermic
27
Which of the following gases is not acidic?
คำตอบ
(D)
CO
28
A hydrocarbon contained 14.3% hydrogen. The empirical formula for the hydrocarbon is [H= 1.0, C= 12.0]
คำตอบ
(B)
\(CH_{2}\)
29
Which of the following statements is NOT a chemical property of an acid?
คำตอบ
(A)
Evolution of ammonia when heated with ammonium salts
30
Halogens generally react with metals to form
คำตอบ
(D)
salts
31
Potassium Chloride solid does not conduct electricity because
คำตอบ
(B)
strong cohesive forces make its ions immobile
32
When water was added to a white anhydrous substance X, the colour changed to blue. X is
คำตอบ
(A)
\(CuSO_{4}\)
33
Solubility curve can be used in the determination of the
คำตอบ
(C)
amount of solid drugs in a given solution
34
If 0.2g of a salt is required to saturate 200\(cm^{3}\) of water at room temperature, what is the solubility of the salt?
คำตอบ
(B)
1.0\(gdm^{-3}\)
35
The property of a chemical reaction that is affected by the presence of a catalyst is
คำตอบ
(A)
activation energy
36
Soluble salts can be prepared by the following methods except
คำตอบ
(C)
double decomposition
37
Chemical reactions occurs when the colliding reactants have energy that is
คำตอบ
(B)
greater than the activation energy
38
The common feature of reactions at the anode is that
คำตอบ
(C)
oxidation is involved
39
Consider the following reaction equation: \(2NO_{(g)} + O_{{2}{(g)}} \to 2NO_{{2}{(g)}}\). What is the change in the oxidation number of nitrogen?
คำตอบ
(C)
+2 to +4
40
Which of the following factors characterize members of the same homologous series?
คำตอบ
(D)
Successive members undergo changes in molecular formula by \(CH_{2}\)
41
Calculate the mass of copper deposited if a current of 0.45A flows through \(CuSO_{4}\) solution for 1hour 15mins. [Cu=64.0, S= 32.0, O =16.0, 1F= 96500C]
คำตอบ
(B)
0.67g
42
Classification of alkanols is based on the
คำตอบ
(D)
number of alkyl groups bonded to the carbon having the hydroxyl group
43
The name of the compound \(C_{4}H_{9}COOC_{3}H_{7}\) is
คำตอบ
(A)
propyl pentanoate
44
Which of the following pairs of gases are pollutants from car exhaust?
คำตอบ
(C)
Carbon(II) oxide and Sulphur(IV) oxide
45
Fats and oils can be obtained from any of the following sources except
