The periodic table is an arrangement of elements according to their?
คำตอบ
(B)
Atomic number
2
A solid with higher melting and boiling points is likely to be?
คำตอบ
(C)
An Electrovalent compound
3
Which of the following metals reacts slowly with cold water?
คำตอบ
(C)
Calcium
4
which of the following elements has the highest ionization energy?
คำตอบ
(C)
Flourine
5
The bleaching action of chlorine is through the process?
คำตอบ
(D)
Oxidation
6
If 6.5g of magnesium ribbon reacts completely with Hydrochloric acid, how many grams of hydrogen gas would be liberated?
Mg(s) + 2 HCl(aq) --> MgCl 2(aq) + H 2(g)
[ H = 1.0, Mg = 24.0 ]
คำตอบ
(A)
0.54g
7
Calcium and magnesium belong to the group of the periodic table because both?
คำตอบ
(D)
have same number of valence electrons
8
Which of the substances is non-polar?
คำตอบ
(A)
Bromine
9
Which of the following pairs of components have the same molecular mass?
[ H = 1.0, C = 12.0, O = 16.0 ]
คำตอบ
(C)
Carbon (ii) Oxide and Ethene
10
When an equilibrium is established between dissolved and undissolved solutes, the solution is said to be?
คำตอบ
(A)
Saturated
11
How many moles of carbon(iv)oxide contains 16.0g of oxygen?
[ C = 12.0, O = 16.0 ]
คำตอบ
(D)
0.50 mol
12
Stoichiometry is based on the law?
คำตอบ
(D)
conservation of mass
13
What is the percentage by mass of H in CH\(_3\)COOH ?
คำตอบ
(C)
6.7%
14
Which of the following compounds has coordinate bonds in its structure?
คำตอบ
(A)
Al\(_2\)Cl\(_6\)
15
The name of the compound CH\(_3\)C(CH\(_3\))\(_2\)CH\(_2\)CH\(_2\)CH\(_3\)
คำตอบ
(D)
2,2 - dimethyl pentane
16
The properties of a good primary standard solution include the following except?
คำตอบ
(B)
low molecular mass
17
What is the solubility of a salt X at 25ºC if the saturated solution of the salt contains 0.28g in 100cm\(^3\) of the solution in mol\dm\(^3\)?
[ X = 56.0g ]
คำตอบ
(A)
0.05
18
Vinegar is an aqueous solution of?
คำตอบ
(C)
ethanoic acid
19
which of the following solutions containing one mole per dm\(^3\) of the compound would have the lowest PH?
คำตอบ
(B)
hydrochloric acid
20
A sample of air was bubbled into water. The PH of the water slowly changed from 7 to 6. Which of the following gases in the samples caused the change?
คำตอบ
(A)
carbon(iv)oxide
21
The most suitable indicator for the reaction between NaOH and HCOOH is?
คำตอบ
(D)
phenolphthalein
22
consider the following reaction equation: 2Al(OH)\(_3\) + 3H\(_2\)SO\(_4\) →Al\(_2\)(SO4)\(_3\)(aq)+6H\(_2\)O. How many moles of tetraoxosulphate(vi)acid is needed to produce 0.5mol of aluminium tetraoxosulphate(vi)?
คำตอบ
(C)
1.5
23
which of the following pairs of substances has the highest heat of neutralization?
คำตอบ
(A)
strong acid and strong base
24
When quicklime dissolves in water?
คำตอบ
(B)
heat is evolved
25
If the value of ΔH is positive for a reaction, it means that the reaction is?
คำตอบ
(B)
endothermic
26
Which of the following compounds is formed by the oxidation of ethanol?
คำตอบ
(D)
CH\(_3\)CO\(_2\)H
27
What is the characteristic of the gas liberated when dilute hydrochloric acid is added to Iron(ii)sulphide?
คำตอบ
(D)
turns lead(ii)ethanoate paper black
28
An organic compound contains 72% carbon, 12% hydrogen and 16% oxygen by mass. What is the empirical formula of the compound?
[ H = 1.0. C = 12.0, O = 16.0 ]
คำตอบ
(B)
C\(_6\)H\(_{12}\)O
29
When excess chlorine is mixed with ethane at room temperature, the product formed is?
คำตอบ
(A)
1,2-dichloroethane
30
which of the following reagents could be used to distinguish between propan-1-ol and propan-2-ol
คำตอบ
(A)
H+ / K2Cr2O7
31
If a catalyst is added to a system, the temperature and the pressure remain constant, there would be no effect on the?
คำตอบ
(D)
heat of reaction
32
consider the following reaction equation: 2NH\(_3 \) .+ 3Cl\(_2\) → N2 + 6HCl.
NH\(_3\) is acting as?
คำตอบ
(A)
a reducing agent
33
The oxidation of chromium in Cr\(_2\)O\(_7)\(-2\) ?
คำตอบ
(C)
+6
34
The process by which alkanoic acid reacts reversibly with alkanols is known as?
คำตอบ
(B)
esterification
35
If the oxidation potential of Mg and Al are +2.37 volts and + 1.66 volts respectively, then the Mg would?
คำตอบ
(D)
replace Al
36
consider the reaction represented by the following equation: 2SO\(_2\) + O\(_2\) ⇌ 2SO\(_3\)
A decrease in the pressure of the reaction would
คำตอบ
(C)
shift the equilibrium position to the left
37
In a mixture of gases which do not react chemically together, the pressure of the individual gas is?
คำตอบ
(D)
partial pressure
38
Biotechnology is applied in the?
คำตอบ
(A)
treatment of sewage
39
which of the following organic compounds has the lowest boiling point?
คำตอบ
(D)
( CH\(_3\) )\(_3\)
40
Consider the following reaction represented by the following equation:
C\(_2\)H\(_2\) \(^{H_2}_{→}\) X \(^{H_2}_{→}\) Y. X and Y respectively are?
คำตอบ
(B)
ethene and ethane
41
Which of the following substances can be classified as heavy chemicals?
คำตอบ
(B)
H\(_2\)SO\(_4\)
42
in Boyle's law?
คำตอบ
(D)
T is constant, V varies inversely with P
43
Which of the following apparatus is NOT used in volumetric analysis?
คำตอบ
(C)
Desiccator
44
One of the deductions from Rutherford's alpha particle scattering experiment is that?
คำตอบ
(C)
nuclei of atoms are positively charged
45
The atoms of \(^{64}_{29}\)Cu and \(^{65}_{30}\)Zn have the same number of?
