How many moles of oxygen molecules would be produced from the decomposition of 2.50 moles of potassium trioxochlorate (V)?
Trả lời
(C)
3.75
4
For iodine crystals to sublime on heating, the molecules must acquire energy that is?
Trả lời
(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?
Trả lời
(A)
EX3 and EX5
6
Two atoms represented as U and U are?
Trả lời
(C)
isotopes
7
As the difference in electronegativity between bonded atoms increases, polarity of the bond?
Trả lời
(B)
increases
8
Which group of elements forms hydrides that are pyramidal in structure?
Trả lời
(C)
V
9
Water has a rather high boiling point despite its low molecular mass because of the presence of?
Trả lời
(A)
hydrogen bonding
10
Argon is used in gas-filled electric lamp because it helps to?
Trả lời
(B)
prevent oxidation of the lamp fillaments
11
The air around a petroleum refinery is most likely to contain?
Trả lời
(C)
SO2, CO and NO2
12
Water can be identified by the use of?
Trả lời
(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?
Trả lời
(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?
Trả lời
(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?
Trả lời
(C)
H3O+ acts as an acid
16
4.0 g of sodium hydroxide in 250 cm3 of solution contains?
Trả lời
(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)
Trả lời
(B)
2
18
Which of the reactions occurs at the anode during the electrolysis of a very dilute aqueous solution of sodium chloride?
Trả lời
(A)
OH- - e → OH
19
The oxidation states of chlorine in HOCL, HCLO3 and HCLO4 are respectively?
Trả lời
(D)
+1, +5 and +7
20
A reaction takes places spontaneously if?
Trả lời
(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)?
Trả lời
(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?
Trả lời
(A)
remains the same
23
NaCI(s) + H2SO4(I) → HCI(g) + NaHSO4(s).
In the reaction above, H2SO4 behaves as?
Trả lời
(A)
a strong acid
24
Which of these gases can be dried with concentrated H2SO4?
Trả lời
(D)
SO2
25
Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating?
Trả lời
(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?
Trả lời
(C)
bubbled through sodium hydroxide solution
27
Which of the following is a property of ionic chlorides?
Trả lời
(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?
Trả lời
(D)
PbBr2(s) + K(aq) + K+(aq) + NO3(aq)
29
Bronze is an alloy of?
Trả lời
(E)
copper and tin
30
The active reducing agent in the blast furnace for the extraction of iron is?
Trả lời
(C)
carbon(II)oxide
31
The fraction of crude oil used as jet fuel is?
Trả lời
(C)
kerosene
32
It is not desirable to use lead tetraethyl as an anti-knock agent because?
Trả lời
(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?
Trả lời
(B)
an amphoteric oxide
34
The carbon atoms on ethane are?
Trả lời
(B)
sp3 hybridized
35
Palm wine turns sour with time because?
Trả lời
(D)
microbial activity results in the production of orgain acids within it
36
Catalytic hydrogenation of benzene produces?
Trả lời
(C)
cyclohexane
37
Which of the following represents saponification?
Trả lời
(D)
Reaction of alkanoates with sodium hydroxide
38
The confirmatory test for alkanoic acids in organic qualitative analysis is the?
Trả lời
(B)
reaction with alkanols to form esters
39
A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?
Trả lời
(C)
sulphide (lV) oxide
40
Which of the curves above represents the behaviour of 1 mole of an ideal gas?
Trả lời
(C)
lll
41
For which salt in the graph above does the solubility increase most rapidly with rise in temperature?
Trả lời
(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
Trả lời
(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?
Trả lời
(C)
Addition of a catalyst
44
The two functional groups in the above compound are
