Elements which belong to the same group in the Periodic Table are characterized by
คำตอบ
(B)
presence of the same number of outermost electrons in the respective atoms
2
The atom of an element X combines with aluminium (\(^{13}\)AI)?
คำตอบ
(D)
AI 2X 3
3
The presence of unpaired electrons in an atom of a transition metal gives rise to
คำตอบ
(A)
paramagnetism
4
What is responsible for metallic bonding?
คำตอบ
(B)
Attraction between the atomic unclei and cloud of electrons
5
Which of the following compounds is covalent?
คำตอบ
(D)
CH4
6
A sheet of paper is placed in the path of a beam from a radioactive source. The emissions that pass through the paper consist of
คำตอบ
(C)
beta particles and gamma rays
7
Which of the following features of a human skeleton can be determined by carbon-dating?
คำตอบ
(C)
Age
8
Which of the following statements about ideal gases is/are correct? 1. The cohesive forces between their particles are negligible ll. They have no definite volume but occupy the volume of their containers III. They are not compressible IV. Their particles collide with loss of energy
คำตอบ
(B)
l and ll only
9
P\(_{TOTAL}\) = P\(_1\) + P\(_2\) + P\(_3\) + ...Pn' where P Total is the pressure of a mixture of gasses. The equation above is an expression of
คำตอบ
(D)
Dalton's law
10
Which of the following pairs of reagents react to produce hydrogen?
คำตอบ
(D)
Magnesium and dilute tetraoxosulphate (VI) acid
11
A mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by
คำตอบ
(D)
filtration
12
Which of the following would dissolve in warm dilute H2SO4 without effervescence, to give a blue solution?
คำตอบ
(A)
Copper turnings
13
In which of the reactions represented by the following equations is HNO3 behaving as a typical acid?
คำตอบ
(A)
CaO + 2HNO3 → Ca(NO3) 2 + H 2O
14
A gas was evolved when a sample of gastric juice reacted with sodium trioxocarbonate (IV) . The gas evolved was
คำตอบ
(D)
CO2
15
It can be concluded that gastric juice
คำตอบ
(B)
is acidic
16
What does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = - 363 kJ mol-1
คำตอบ
(B)
Electron affinity
17
Consider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = - 65.7 kJmol-1. From the equation, it can be deduced that
คำตอบ
(B)
a solid is formed and heat is evolved
18
A reaction is represented by the equation below. A2(g) + B2(g) → 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct?
คำตอบ
(D)
Pressure has no effect on the equilibrium mixture
19
What is the oxidation number of nitrogen in Al(NO\(_3\))\(_3\)?
คำตอบ
(C)
+ 5
20
What is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O
คำตอบ
(D)
Copper
21
Which of the following substances decomposes when an electric current is passed through it?
คำตอบ
(C)
Hydrochloric acid
22
A concentrated solution containing H+, Cu2+,OH- and CI- was electrolyzed using platinum electrodes which of the ions will be discharged at the cathode?
คำตอบ
(B)
Cu2+
23
Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible?
คำตอบ
(B)
Q + S+ → S + Q+
24
In the electrolysis of CuSO4(aq) using copper electrodes, the reaction at the anode is
คำตอบ
(C)
dissolution of copper electrode
25
A feasible cell was constructed by joining the two half cells below. Cu\(^{2+}\) (aq) + 2e\(^-\) → Cu(s) E\(^0\) = +0.34 V; Zn\({^2+}\) + 2e\(^-\) → Zn\((_s)\) E\(^0\) = - 0.76V. What is the standard e.m.f. of the cell?
คำตอบ
(D)
+1.1V
26
Hydrogenation of butene yields
คำตอบ
(B)
butane
27
Benzene produces more soot than ethene on burning because benzene
คำตอบ
(A)
has a higher molar mass
28
One of the products of combustion of pentane in excess air is
คำตอบ
(D)
carbon (IV) oxide
29
Which of the following polymers contains nitrogen?
คำตอบ
(A)
Nylon
30
What is the function of H2SO4 in the following reaction?
C12H22O11 conc. H2SO4 → 12C + 11H2O
คำตอบ
(C)
Dehydrating agent
31
Which of the following constitutes an advantage in the use of hard water?
คำตอบ
(D)
Formation of strong bones
32
Sugars can be hydrolyzed at room temperature by the action of
คำตอบ
(C)
enzymes
33
If 10 cm 3 of distilled water is added to 10 cm3 of an aqueous salt solution, the concentration of the solution
คำตอบ
(B)
decreases
34
Which of the following reactions represents the change that occurs when a photographic film is exposed to sunlight?
คำตอบ
(B)
Ag+ + e- → Ag
35
Acidic industrial waste can be treated with
คำตอบ
(A)
lime
36
Waste plastics accumulate in the soil and pollute the environment because plastic materials are
คำตอบ
(B)
non-biodegradable
37
The conclusion from Rutherford's radioactive substance alpha-scattering experiment is that
คำตอบ
(A)
atoms are mostly empty space with a samll
38
If a metal R forms a compound with the formula R(NO3)2 the formula of its tetraoxosulphate (VI) is
คำตอบ
(B)
RSO4
39
Which of the following decreases when a given mass of gas is compressed to half its initial volume?
คำตอบ
(A)
Average intermolecular distance
40
What volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure? The equation for the reaction is 2NH3(g) → N2(g) + 3H2(g)
คำตอบ
(B)
150cm3
41
The gas given off when NH4Cl is heated with an alkali is
คำตอบ
(D)
NH 3
42
A major factor considered in selecting a suitable method for preparing a simple salt is its
คำตอบ
(D)
solubility in water
43
Which of the following acids forms normal salts only?
คำตอบ
(D)
Trioxonitrate (V) acid
44
A substance is said to be hygroscopic if it absorbs?
คำตอบ
(D)
moisture from the atmosphere without dissolving
45
Which of the following substances increases in mass when heated in air?
คำตอบ
(C)
magnesium ribbon
46
Calculate the mass of sodium hydroxide in 5.00 dm3 of a 0.125 mol dm-3 solution [NaOH = 40 g mol]
คำตอบ
(D)
25. 0 g
47
Which of the following salt solutions will have a pH greater than 7?
คำตอบ
(B)
Na2CO3(aq)
48
What will happen if more heat is applied to the following system at equilibrium? X2(g) + 3Y 2(g) ⇌ 2XY3(g); ∆H =-kJmol -1
คำตอบ
(B)
more of XY3 will decompose
49
Equal amounts of marble chips are reacted separately with 100cm3 of hydrochloric acid of different concentrations . if all the marble chips reacted, which of the following remained the same in each case?
คำตอบ
(B)
Total mass of gas evolved during the reaction
50
CuSO4 5H2O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by
