Which of the following substances is an example of a fine chemical?
คำตอบ
(C)
Ethylene
2
The IUPAC name of the compound represented by the structure below is ?
คำตอบ
(A)
2- chloro but-I ,3-diene.
3
Which or the following substances is a polypeptide?
คำตอบ
(C)
Protein
4
Which or the following products could be formed during incomplete combustion of a hydrocarbon.
i.Carbon ii. Hydrogen III. Carbon (Il) oxide
คำตอบ
(C)
I and III only
5
What quantity of electrons is lost when one mole of iron (II) ions is oxidized to iron (III) ?
คำตอบ
(B)
3 moles
6
What is the mass of silver deposited when 24,125 C of electricity is passed through a solution or silver salt.
[Ag = 108, IF = 96,500 C ]
คำตอบ
(D)
27g
7
Equal masses of calcium trioxocarbonate(iv) were added to dilute hydrochloric acid at the temperature specified. Under which of the following conditions would the reaction be slowest?
คำตอบ
(A)
Calcium trioxocarbonate ( iv ) chips a 20°C
8
The high solubility of ethanol in water is due to?
คำตอบ
(D)
hydrogen bonding
9
Which of the following pairs of properties of alkali metals decreases down the group?
คำตอบ
(D)
First ionization energy and melting point
10
The most suitable process of obtaining water from an aqueous solution of sugar i
คำตอบ
(B)
Distillation
11
Group VIl elements in their combined states are called?
คำตอบ
(C)
Halide
12
When an ionic bond is broken, bonding electrons are
คำตอบ
(B)
gained by the most electropositive atom
13
The oxidation state of chlorine in NaClO\(_3\) is?
คำตอบ
(C)
+5
14
A balanced chemical equation is based on the law of?
คำตอบ
(D)
Conservation of mass
15
Which of the following pairs of elements has the greatest difference in electronegativity?
คำตอบ
(A)
Na and F
16
A factor that is considered most important when siting a chemical industry is?
คำตอบ
(B)
nearness to raw materials
17
The boiling point of pentane is higher than that of propane because?
คำตอบ
(B)
Pentane has more covalent bonds to break
18
Which of the following solids would not decompose on heating?
คำตอบ
(C)
Potassium trioxocarbonate (IV)
19
The following molecules have double covalent bonds between two atoms except?
คำตอบ
(D)
water
20
The type of isomerism exhibited by cis and trans isomers is?
คำตอบ
(B)
geometrical
21
Which of the following compounds has the lowest boiling point?
คำตอบ
(A)
C\(_4\)H\(_10\)
22
An alkanol containing 60% carbon by mass would have a molecular formula [H=1.0. C-12.0, O= 16.0]
คำตอบ
(C)
C\(_3\)H\(_7\)OH
23
Which of the following compounds would release hydrogen when reacted with sodium metal?
I. CH\(_3\)COOH
II. CH\(_3\)CH\(_2\)OH
III. CH\(_3\)COOCH\(_3\)
คำตอบ
(B)
I and II only
24
Which of the following substances is not a reducing agent?
คำตอบ
(C)
O\(_2\)
25
Which of the following statements is correet for a reaction at equilibrium?
คำตอบ
(C)
The rates of the forward and backward reactions are equal
26
Which of the following reactions are always exothermic? 1. Neutralization Il. Decomposition III. Combustion
คำตอบ
(B)
I and III only
27
Which of the following standard conditions is not correct about energy changes?
คำตอบ
(D)
ΔH at 298 K is the activation energy
28
f 5.0 cm\(^-3\) of 0.200 mol dm(^-3\) Na\(_2\)CO\(_3\) was diluted to 250cm(^-3\) solution, what would be the concentration of the resulting solution?
คำตอบ
(A)
0.004 mol dm(^-3\)
29
The initial volume and pressure of a given mass of gas is V and 3.P. What is its pressure if its volume is increased to 2V at constant temperature?
คำตอบ
(C)
\(frac{3}{2}\) P
30
What volume of oxygen at s.t.p is required to burn completely 7.5 dm\(^3\) of methane according to the following equation?
When 250 cm3 of a saturated solution of CuSO\(_4\) at 30°C was evaporated to dryness, 5.0 g of the salt was obtained..
What is the solubility of the salt at 30°C? [CuSO\(_4\) = 160]
คำตอบ
(B)
0.125
32
The bond between NH\(_3\) and H\(^+\) in NH4\(^+\) is?
คำตอบ
(A)
dative
33
Which of the following oxides has a giant covalent structure?
คำตอบ
(D)
SiO\(_2\)
34
Which of the following hydroxides is not readily soluble in water?
คำตอบ
(B)
Ca(OH)\(_2\)
35
Which of the following statements about the solubility of a salt is correct?
คำตอบ
(C)
Crystallization would be efficient in separating out a salt whose solubility increases considerably with temperature
36
How many moles of H\(_2\)SO4 are there in 50 cm\(^3\) of 0.108 mol dm\(^3\) solution of the acid?
คำตอบ
(B)
5.4 x 10\(^{-3}\)
37
If 20 cm\(^3\) of sodium hydroxide was neutralized by 20 cm\(^3\) of 0.01 mol dm\(^3\) tetraoxosulphate(VI) acid, what is the concentration of the sodium hydroxide solution?
คำตอบ
(B)
0.020
38
"Electrons always occupy the lowest empty energy level" is a statement of
คำตอบ
(A)
Aufbau Principle
39
Which of the following metals does not react with water to produce hydrogen?
คำตอบ
(A)
Copper
40
Which of the following arrangement of elements is in decreasing order of electronegativity?
คำตอบ
(D)
P, Si, Al, Mg, Na
41
The metallic bond in magnesium is stronger than that in calcium because magnesium has a
คำตอบ
(B)
smaller atomic size
42
Consider the reaction represented by the following equation:
AgNO\(_3\) + NaCl → AgCl + NaNO\(_3\).
The steps that could be taken to obtain pure dry sample of AgCI (s) from the mixture includes
คำตอบ
(C)
filtering, washing and drying
43
How many electrons does \({31}_{15}\)P\(^3-\) contain?
คำตอบ
(D)
18
44
The atomic number of an atom would be equal to its mass number if it
คำตอบ
(C)
does not contain neutrons
45
Which of the following processes is not exhibited by atoms in order to attain more stable electron configuration?
