X is a crystalline salt of sodium solution of X in water turns litmus red and produces a gas which turns lime water milky when added to sodium carbonate. With barium chloride solution, X gives hydrochloric acid. X is
คำตอบ
(C)
NaHSO 4
2
The alkanol obtained from the production of soap is
คำตอบ
(B)
glycerol
3
The flame used by welders in cutting metals is
คำตอบ
(D)
oxy-acetylene flame
4
Consecutive members of an alkane homologous serires differ by
คำตอบ
(B)
CH2
5
If an element has the electronic configuration 1s 2 2s2 2p3 3s2 3p4, it is
คำตอบ
(D)
a p-Block element
6
Some copper (ll) sulphate pentahydrate (CuSO4 5H2O), was heated at 120 oC with the following results. Wt of crucible = 10.00 g; Wt of crucible + CuSO4 5H2O =14.98g; Wt of crucible + residue = 13.54 g. How many molecules of water of crystalization were lost?
[H = 1, Cu = 63.5, O = 16, S = 32]
คำตอบ
(D)
4
7
The three-dimensional shape of methane is
คำตอบ
(D)
tetrahedral
8
An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.
Compound W is
คำตอบ
(D)
an ester
9
An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.
The molecular formula of X is
คำตอบ
(B)
C6H12O6
10
An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.
Reaction of X with yeast forms the basis of the
คำตอบ
(C)
brewing industry
11
A mixture of common salt, ammonium chloride and barium sulphate can best be separated by
คำตอบ
(C)
sublimation followed by addition of water then filtration
12
Which of the following relationships between the pressure P, the volume V and the temperature T, represents an ideal gas behaviour?
คำตอบ
(B)
P \(\alpha\) T/V
13
The colour imparted to a flame by calcuium ion is
คำตอบ
(C)
brick-red
14
In the reaction M + N P;∆H = + QKJ. Which of the following would increase the concentration of the product?
คำตอบ
(E)
Increasing the temperature
15
In which of the following processes is iron being oxidized?
1 Fe + H2SO4 → FeSO4 +H2
2 FeSO4 + H2S → FeS + H2SO4
3 2FeCI2 + Cl2 → 2FeCl3
4 2FeCl3 + SnCl2 + → 2FeCl2 + SnCl4
คำตอบ
(D)
1 and 3
16
In the reaction Fe + Cu2+ \(\to\) Fe2+ + Cu,iron displaces copper ions to from copper. This is due to the fact that
คำตอบ
(E)
iron is higher in the electrochemical series than copper
17
The correct name of the compound with the above structural formula is
คำตอบ
(A)
2-methylbut -1-ene
18
How many isomeric forms are there for the molecular formula C3H6Br2?
คำตอบ
(D)
4
19
A piece of burning sulphur will continue to burn in a gas jar of oxygen to give misty fumes which readily dissolved in water. The resulting liquid is
คำตอบ
(C)
trioxosulphate (IV) acid
20
Sodium sulphate decahydrate (Na2SO4.10 H2O) on exposure to air loses all its water of crystallization.
The process of loss is known as
คำตอบ
(A)
efflorescence
21
Which of the following happens during the electrolysis of molten sodium chloride?
คำตอบ
(E)
Chloride ion is oxidized
22
Crude petroleum pollutant usually seen on some Nigerian creeks and waterways can be dispersed or removed by
คำตอบ
(C)
pouring organic solvents to dissolve the petroleum
23
An element is electronegative if
คำตอบ
(D)
it has a tendency to gain electrons
24
Solutions X, Y, and Z have PH values 3.0. 5. 0 and 9. 0 respectively. Which of the following statements is correct?
คำตอบ
(E)
Z is the least acidic
25
In the reactions
(I) H2 (g) + 1/2O2(g) → H2O(l); ∆H = -286 KJ
(II) C(s) + O2g) → CO2 (g); ∆H = -406 KJ the equations imply that
คำตอบ
(C)
less heat is evolved in (l)
26
Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI?
คำตอบ
(D)
Mg and Fe only
27
Stainless steel is an alloy of
คำตอบ
(B)
carbon, iron and chromium
28
Which volume of 0.5 M H 2SO4 will exactly neutralize 20 cm 3 of 0.1 M NaOH solution?
คำตอบ
(A)
2.0 cm 3
29
Which of the following pair of gases will NOT react further with oxygen at a temperature between 30oC AND 400oC
คำตอบ
(C)
NO2 and SO3
30
Some metals are extracted from their ores after some preliminary treatments by electrolysis (L), some by thermal decomposition(T), some by a combination of both processes (TL). Which set-up in the following for the extraction of iron, copper, and aluminium is correct?
คำตอบ
(E)
lron (T) copper (L), aluminium (TL)
31
In the preparation of some pure crystals of Cu (NO3)2 starting with CuO, a student gave the following statements as steps he employed. Which of these shows a flaw in his report ?
คำตอบ
(A)
some CuO was reacted with excess dilute H2SO4
32
Which of the following separation processes is most likely to yield high quality ethanol (>95%) from palm wine?
คำตอบ
(C)
fractional distillation with a dehydrant
33
Increasing the pressure of a gas
คำตอบ
(D)
increases the density of the gas
34
2.5 g of a hydrate barium salt gave on heating, 2.13 g of the anhydrous salt. Given that the relative molecular mass of the of the anhydrous salt is 208, the number of molecules of water of crystallization of the barium salt is
คำตอบ
(D)
2
35
3. 06 g of a sample of potassium trioxochlorate (V) (KCIO\(_3\)) was required to make a saturated solution with 10cm\(^3\) of water at 25°C. The solubility of the salt at 25°C is [K =39, Cl = 35.5, O = 16]
คำตอบ
(C)
2.5 moles dm3
36
The cracking process is very important in the petroleum industry because it.
คำตอบ
(C)
yields more engine fuels
37
A gas that can behave as a reducing agent towards chlorine and as an oxidizing agent toward hydrogen sulphide is
คำตอบ
(C)
SO2
38
Which of the following solutions will give a white precipitate with barium chloride solution and a green flame test?
คำตอบ
(B)
CuSO4
39
The mass of an atom is determined by
คำตอบ
(D)
the number of neutrons and protons
40
Which of the following is a neutralization reaction?
คำตอบ
(E)
Addition of trioxonitrate (V) acid (nitric acid) to potassium hydroxide solution
41
A jet plane carrying 3,000 kg of ethane burns off all the gas forming water and carbondioxide. if all the carbondioxide is expelled and all the water formed is condensed and kept on board the plane, then the gain in weight is
คำตอบ
(D)
2, 400 kg
42
Liquid X, reacts with sodium trioxocarbonate (IV) (Na2CO3) to give a gas which turns calcium chloride solution milky X is
คำตอบ
(D)
an acid
43
Which of the following statements is FALSE?
คำตอบ
(B)
Sodium metal dissolves in water giving oxygen
44
When sodium dioxonitrate (lll) (NaNO2) dissolves in water, ∆H is positive. The process of dissolution is
คำตอบ
(B)
endothermic
45
The equilibrium reaction between copper (l) chloride and chlorine at 25oC and 1 atmosphere is represented by the equation:
2CuCl +Cl2 ⇌ 2 CuCl2 ∆H = - 166 KJ. Which of the following statements is TRUE for the reaction, pressure remaining constant?
