The energy change which accompanies the addition of an electron to a gaseous atom is
คำตอบ
(B)
electron affinity
3
Which of the following elements is a d-block element?
คำตอบ
(B)
lron
4
Which of the following statements about chlorine and iodine at room temperature is correct?
คำตอบ
(A)
Chlorine is gas and iodine is solid
5
If X is a group lll element, its oxide would be represented as
คำตอบ
(C)
X2O3
6
Which of the following species correctly represented an ion of M with 13 protons and 10 electrons?
คำตอบ
(C)
13M 3+
7
A solid substance with high melting and boiling points is likely to be a/an
คำตอบ
(C)
electrovalent compound
8
Which of the following molecules has a linear shape?
คำตอบ
(B)
CO 2
9
Which of the following molecules has a triple bond in its structure?
คำตอบ
(C)
N2
10
The bonds in crystaline ammonium chloride are?
คำตอบ
(C)
ionic covalent and dative
11
Consider the neutralization reaction represented by the following equation: Na2CO3 + 2HNO 3 → 2NaNO3 + H2O + CO2 The stoichiometric ratio of acid to base is
คำตอบ
(B)
2:1
12
A solution of sodium trioxocarbonate (IV) contains 10.6g in 250cm3 of solution. Calculate the concentration of the solution. [Na2CO3 = 106.0]
คำตอบ
(A)
0.4 mol dm-3
13
What is the volume occupied by 2 moles of ammonia at s.t.p?
คำตอบ
(A)
44.8 dm-3
14
Which of the following apparatus can be used to measure accurately a specific volume of a liquid?
คำตอบ
(D)
Pipette
15
A given volume of oxygen diffused through a porous partition in 8 seconds. How long would it take the same volume of carbon (IV) oxide to diffuse under the same condition? [C = 12.0, O = 16.0]
คำตอบ
(C)
9.4 seconds
16
Which of the following gases contains the highest number of atoms at s.t.p?
คำตอบ
(A)
6 moles of neon
17
The determination of heat of combustion is carried out with
คำตอบ
(B)
a bomb calorimeter
18
The minimum amount of energy required for effective collisions between reacting particles is known as
คำตอบ
(A)
activation energy
19
Which of the following oxides is basic?
คำตอบ
(D)
CaO
20
Which of the following equimolar solutions would have the highest conductivity?
คำตอบ
(B)
NaNO3(aq)
21
The following substances are normal salts except
คำตอบ
(C)
Mg(OH)NO3
22
Which of the following chlorides is insoluble in water?
คำตอบ
(A)
AgCI
23
Which of the following factors would not affect the solubility of a gas?
คำตอบ
(A)
Concentration
24
Consider the equilibrium reaction represented by the following equation: 2SO2(g) + O2(g) ⇌ 2SO3(g); ∆H = 395.7 kJmol-1 Which of the following statements about the equilibrium system is correct?
คำตอบ
(C)
Decrease in pressure increases the equilibrium concentration of O2
25
The rate of chemical reaction of solids are not affected by
คำตอบ
(B)
pressure
26
Which of the following statements about the cell notation Mg/Mg\(^{2+}\)//Cu\(^{2+}\)/Cu is correct?
คำตอบ
(C)
Magnesium is the anode
27
Which of the following statements about the electrolysis of CuSO4(aq) using copper cathode and platinum anode is not correct?
คำตอบ
(C)
it is used for the purification of copper
28
What is the change in oxidation number of manganes in the reaction represented by the following equation? MnO-4(aq) + 8H+(aq) + 5e- → Mn2+(aq) + 4H2O(l)
คำตอบ
(D)
+ 7 to 2
29
The quantity of electricity required to discharge 1 mole of univalent ion is
คำตอบ
(C)
96,500 C
30
Fact and oils are used as raw materials in the following industries except
คำตอบ
(B)
plastic industry
31
An advantage of detergent over soap is that detergents
คำตอบ
(D)
lather readily with water
32
The products of fermentation of sugar are
คำตอบ
(B)
ethanol and carbon (IV) oxide
33
The IUPAC name of C2H6COOC2,/sub>H6 is
คำตอบ
(B)
ethylproanoate
34
An organic compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. What is the empirical formula of the compound? [O = 16.0, C = 12.0, H = 1.0]
คำตอบ
(C)
CH2O
35
Compound N reacts with sodium metal to produce a gas that gives a 'pop' sound with a burning splint N also react with ethanoic acid to give a sweet smelling liquid. Compound N is an
