When steam is passed over white-hot coke, the products are
คำตอบ
(B)
carbon (II) oxide and hydrogen
2
The maximum number of electrons that can accommodated in the shell having the principal quantum number 3 is
คำตอบ
(D)
18
3
Methanol is obtained from wood by
คำตอบ
(E)
destructive distillation
4
Study carefully the reaction represented by the equation below. 2H2O 2(l) → O 2(g) + 2H2O(l). Which of the following will not reaction increase the reaction rate?
คำตอบ
(D)
Adding water to the reactant
5
Which of the following processes is a physical reaction?
คำตอบ
(C)
Allotropic change
6
If the volume of a given mass of gas at 298 K and pressure of 205.2 x 10\(^3\) Nm\(^{-2}\) is 2.12dm\(^3\), what is volume of the gas at s.t.p? (Standard pressure = 101.3 x 10\(^3\) Nm\(^{-2}\), Standard temperature = 273K)
คำตอบ
(D)
3.93dm3
7
The following acids are monobasic except
คำตอบ
(C)
ethanedioic acid
8
The reactions ethyne are mainly
คำตอบ
(B)
addition reactions
9
When air is passed through potash and then pyrogallol, the components are noble gases,
คำตอบ
(C)
nitrogen and water vapour
10
The halide used widely in photography is
คำตอบ
(C)
silver bromide
11
The scum formed when soap is mixed with hard water could be
คำตอบ
(A)
calcium trioxocarbonate (IV)
12
What is the quantity of electricity produced when a current of 0.5A is passed for 5 hours 45 mins? (1F = 96500C)
คำตอบ
(A)
0. 11F
13
''The rate a reaction is proportional to the number of effective collisions occurring per second between the reactants''. This statement is associated with the
คำตอบ
(D)
collision theory
14
What is the following compounds will not decompose when heated strongly ?
คำตอบ
(B)
K2CO3
15
What is the change in the oxidation number of phosphorus in the the reaction represented by the following equation? 4P (s) + 5O(2)(g) → 2P2O5(g)
คำตอบ
(B)
0 to 5
16
When iron rusts, it undergoes
คำตอบ
(D)
redox reaction
17
Consider the compounds represented by the following general formula: X2SO4 Y2(SO4)3, 24H2OX and Y could respectively be
คำตอบ
(A)
K and AI
18
Which of the following involves the decomposition enzymic action?
คำตอบ
(B)
Fermentation
19
The following salts are readily soluble in water except
คำตอบ
(D)
CuCO3
20
When sucrose is warmed with Fehling's solution
คำตอบ
(D)
there is no precipitate
21
Which of the following gases will have the highest rate of diffusion under the same conditions? (H = 1, C =12, O = 16, S = 32, CI = 35.5)
คำตอบ
(A)
O2
22
The formula (CH3),3 COH is that of a
คำตอบ
(C)
tertiary alkanol
23
What is the number of oxygen atoms in 32g of the gas? (O = 16, L = 6.0 X 10\(^{23}\) mol\(^{-1}\))
คำตอบ
(B)
6.0 X 1023
24
Which of the following compounds is not correct about the reaction of sodium material for the manufacture of plastics?
คำตอบ
(B)
Ethane
25
The energy required to remove the most loosely bound electron from an atom in the gaseous state is known as the
คำตอบ
(B)
ionization energy
26
Vulcanization of rubber
คำตอบ
(D)
hardnes the rubber through cross-linkage
27
If a reaction is said to be exothermic, which of the following statements is a correct deduction from the information?
คำตอบ
(A)
the reaction vessel gets hotter as the reaction proceeds
28
If a reaction is said to be exothermic, which of the following statements is a correct deduction from the information?
คำตอบ
(A)
the reaction vessel gets hotter as the reaction proceeds
29
Which of the following statement is not correct about esterification?
คำตอบ
(C)
it is similar to hydrolysis
30
Which of the following statements is not correct? The 4s orbital
คำตอบ
(B)
is of higher energy than the 3d orbital
31
Which of the following pH values is likely to be that of a slightly alkaline solution?
คำตอบ
(D)
8
32
Which of the following minerals contains flurine as one of its constituent elements?
คำตอบ
(A)
Cryolite
33
The product of the reaction between propanoic acid and ethanol is
คำตอบ
(E)
ethylpropanoate
34
Which of the following groups contains entirely linear molecules?
คำตอบ
(D)
CO2H2N2
35
What is the value of n in the following equation? XO-4 +8H + + ne- → X2 + + 4H2O
