The presence of an impurity in substance will cause the melting point to
คำตอบ
(B)
reduce
2
What volume of carbon (ll) oxide is produced by reacting excess carbon with 10 dm3 of oxygen?
คำตอบ
(B)
20 dm 3
3
The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is
คำตอบ
(C)
cobalt-60
4
The shape of the carbon (lV) oxide molecule is
คำตอบ
(B)
linear
5
Which of the following molecules is held together by hydrogen bond?
คำตอบ
(D)
HF
6
The bond formed between two elements with electron configurations 1s2 2s2 2p6 3s2 and 1s2 2s2 2p4 is
คำตอบ
(D)
ionic
7
The constituent of air that acts as a diluent is
คำตอบ
(A)
nitrogen
8
Steam changes the colour of anhydrous cobalt (ll) chloride from
คำตอบ
(C)
blue to pink
9
An example of a hygroscopic substance is
คำตอบ
(A)
CuO (S).
10
The solvent used for removing grease stain is
คำตอบ
(B)
ammonia solution
11
In a water body, too much sewage leads to
คำตอบ
(C)
an increase in the bacterial population which reduces the level of oxygen in the water
12
10.0 dm3 of water was added to 2.0 mol dm-3 of 2.5dm3 solution of HCl. What is the concentration of the final solution in mol dm-3?
คำตอบ
(A)
0.4
13
Three drops of a 1.0 mol dm-3 solution of HCl was added to 20 cm3 of a solution of pH6.4. The pH of the resulting solution will be
คำตอบ
(B)
less than 6.4
14
Which of the following substances is not a salt?
คำตอบ
(A)
Aluminium oxide
15
An insoluble salt can be prepared by
คำตอบ
(B)
double decomposition
16
2H2O (l) + 2F2(g) → 4HF(aq) + O2(g).
In the reaction above, the substance that is being reduced is
คำตอบ
(C)
F2(g)
17
In an electrochemical cell, polarization is caused by
คำตอบ
(D)
hydrogen
18
In an endothermic reaction, if there is a loss in entropy the reaction will
คำตอบ
(C)
not be spontaneous
19
the minimum amount of energy required for a reaction to take place is
คำตอบ
(C)
activation energy
20
Which of the following compounds is a neutral oxide?
คำตอบ
(D)
Carbon (ll) oxide
21
In the laboratory preparation of ammonia, the flask is placed in a slanting position so as to
คำตอบ
(A)
prevent condensed water from breaking the reaction flask
22
Which of the gases is employed as an anaesthesia?
คำตอบ
(A)
N 2O
23
Sulphur (IV)oxide is a strong reducing agent in the presence of water due to the formation of
คำตอบ
(D)
trioxosulphate (IV) salt
24
A metal that forms soluble trioxosulphate (IV) ion is
คำตอบ
(B)
potassium
25
Copper is displaced from the solution of its salts by most metals because it
คำตอบ
(B)
is at the bottom of the activity series
26
The coloured nature of transition metal ions are associated with their partially filled
คำตอบ
(D)
d-orbital
27
Aluminium containers are frequently used to transport trioxonitrate (V) acid because aluminium
คำตอบ
(C)
does not react with the acid
28
2- methylpropan-2-ol is an example of a
คำตอบ
(B)
tertiary alkanol
29
The reaction between ammonia and ethyl ethanoate produces
คำตอบ
(D)
ethanol and ethanamide
30
The decarboxylation of ethanoic acid will produce carbon (IV)oxide and
คำตอบ
(A)
methane
31
A primary amide is generally represented by the formula
คำตอบ
(B)
RCONH 2
32
Which of the following fraction is used as raw material for the cracking process?
คำตอบ
(D)
diesel oils
33
An organic compound contains 60% carbon, 13.3% hydrogen and 26.7% oxygen. Calculate the empirical formula rn(C=12,H =1, O=16)
คำตอบ
(B)
C 3H 8O
34
From the diagram above, an ideal gas is represented by
คำตอบ
(A)
Z
35
In the graph above, the activation energy of the catalyzed reaction is
คำตอบ
(A)
100KJ
36
Choose the correct option from the graph above . 3Fe(S) + 4H2O(g) ⇌ Fe3O4(s) + 4H2(g). The equilibrium constant, K, of the reaction above is represented as
คำตอบ
(C)
C
37
The IUPAC nomenclature for the compound above is
คำตอบ
(A)
4-methylpent-1-ene
38
Use the above option to answer this question. The dehydration of ammonium salt of alkanoic acids produces a compound with the general formula
คำตอบ
(B)
B
39
Use the following option above to answer this question. Which of the following compounds in solution will turn red litmus paper blue?
