How many moles of oxygen molecules would be produced from the decomposition of 2.50 moles of potassium trioxochlorate (V)?
إجابة
(C)
3.75
4
For iodine crystals to sublime on heating, the molecules must acquire energy that is?
إجابة
(D)
greater than the forces of attraction in both the solid and the liquid phases
5
An element, E, has the electronic configuration 1s22s22p63s2p3. The reaction of E with a halogen X can give?
إجابة
(A)
EX3 and EX5
6
Two atoms represented as U and U are?
إجابة
(C)
isotopes
7
As the difference in electronegativity between bonded atoms increases, polarity of the bond?
إجابة
(B)
increases
8
Which group of elements forms hydrides that are pyramidal in structure?
إجابة
(C)
V
9
Water has a rather high boiling point despite its low molecular mass because of the presence of?
إجابة
(A)
hydrogen bonding
10
Argon is used in gas-filled electric lamp because it helps to?
إجابة
(B)
prevent oxidation of the lamp fillaments
11
The air around a petroleum refinery is most likely to contain?
إجابة
(C)
SO2, CO and NO2
12
Water can be identified by the use of?
إجابة
(A)
anhydrous copper (II) tetraoxosulphate (VI)
13
The phenomenon whereby sodium trioxocarbonate (IV) decahydrate loses some of its water of crystallization on exposure to the atmosphere is known as?
إجابة
(D)
efflorescence
14
A student prepares 0.5 M solution each of hydrochloric and ethanoic acids and then measured pH. The result would show that the?
إجابة
(D)
ethanoic acid solution has a higher pH
15
NH\(_3\) + H\(_3\)O\(^+\) → NH\(_4\)\(^+\) + H\(_2\)O. It may be deduced from the reaction above that?
إجابة
(C)
H3O+ acts as an acid
16
4.0 g of sodium hydroxide in 250 cm3 of solution contains?
إجابة
(A)
0.40 moles per dm3
17
During the electrolysis of a salt of a metal M, a current of 0.5 A flows from for 32 minutes 10 seconds and deposits 0.325 g of M, What is the charge of the metal ion?
(M = 65, If = 96,500 C per mole of electron)
إجابة
(B)
2
18
Which of the reactions occurs at the anode during the electrolysis of a very dilute aqueous solution of sodium chloride?
إجابة
(A)
OH- - e → OH
19
The oxidation states of chlorine in HOCL, HCLO3 and HCLO4 are respectively?
إجابة
(D)
+1, +5 and +7
20
A reaction takes places spontaneously if?
إجابة
(C)
∆H < T ∆S
21
The standard enthalpies of formation of CO2(g), H2O(g) and CO(g) in kJ mol- are -394, -242 and -110 respectively. What is the standard enthalpy change for the reaction CO(g) + H2(g)O → CO2(g) + H2(g)?
إجابة
(A)
-42 KJ mol-
22
10g of a solid is in equilibrium with its own vapour.
When 1 g of a small amount of solid is added, the vapour pressure?
إجابة
(A)
remains the same
23
NaCI(s) + H2SO4(I) → HCI(g) + NaHSO4(s).
In the reaction above, H2SO4 behaves as?
إجابة
(A)
a strong acid
24
Which of these gases can be dried with concentrated H2SO4?
إجابة
(D)
SO2
25
Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating?
إجابة
(A)
Silver and trioxonitrate (V)
26
An experiment produces a gaseous mixtures of carbon (IV) oxide and carbon (II) oxide. In order to obtain pure carbon (II) oxide, the gas mixture should be?
إجابة
(C)
bubbled through sodium hydroxide solution
27
Which of the following is a property of ionic chlorides?
إجابة
(B)
They react with aqueous AgNO3 to give a white precipiate which is soluble in excess ammonia
28
When dilute aqueous solutions of lead (II) nitrate and potassium bromide are mixed, a precipitate is observed.
The products of this reaction are?
إجابة
(D)
PbBr2(s) + K(aq) + K+(aq) + NO3(aq)
29
Bronze is an alloy of?
إجابة
(E)
copper and tin
30
The active reducing agent in the blast furnace for the extraction of iron is?
إجابة
(C)
carbon(II)oxide
31
The fraction of crude oil used as jet fuel is?
إجابة
(C)
kerosene
32
It is not desirable to use lead tetraethyl as an anti-knock agent because?
إجابة
(B)
of pollution effects from the exhaust fumes
33
Al2O3(s) + 3H2SO4(aq) → Al2(SO4(aq)) + 3H2(I)O
Al2O3(s) + 2NaOH(aq)) + 3H2(I)O → 2NaAl(OH)4(aq)).
We can conclude from the equations above that Al2O3(s) is?
إجابة
(B)
an amphoteric oxide
34
The carbon atoms on ethane are?
إجابة
(B)
sp3 hybridized
35
Palm wine turns sour with time because?
إجابة
(D)
microbial activity results in the production of orgain acids within it
36
Catalytic hydrogenation of benzene produces?
إجابة
(C)
cyclohexane
37
Which of the following represents saponification?
إجابة
(D)
Reaction of alkanoates with sodium hydroxide
38
The confirmatory test for alkanoic acids in organic qualitative analysis is the?
إجابة
(B)
reaction with alkanols to form esters
39
A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?
إجابة
(C)
sulphide (lV) oxide
40
Which of the curves above represents the behaviour of 1 mole of an ideal gas?
إجابة
(C)
lll
41
For which salt in the graph above does the solubility increase most rapidly with rise in temperature?
إجابة
(B)
KNO3
42
Half-cell reaction. From the data above , it can be deduced that the most powerful reducing agent of the four metals is
إجابة
(C)
Ba
43
In the diagram above, curve X represents the energy profile for a homogeneous gaseous reaction. Which of the following conditions would produce curve Y for the same reaction?
إجابة
(C)
Addition of a catalyst
44
The two functional groups in the above compound are
