Chromatography is used to separate components of mixtures which differ in their rates of?
إجابة
(B)
migration
2
Which of the following is a example of a chemical change?
إجابة
(B)
Rusting of iron
3
The number of hydrogen ions in 4.9 g of tetraoxosulphate (IV) acid is?
(S = 32, O =16, H = 1, Avogadro Number = 6.02 x 10\(^{23}\) )
إجابة
(B)
6.02 x 1022
4
What volume of oxygen will remain after reacting 8cm\(^3\) of hydrogen with 20cm\(^3\) of oxygen?
إجابة
(D)
16 cm3
5
A gas sample with an initial volume of 3.25 dm3 is heated and allowed to expand to 9.75 dm3 at constant pressure. What is the ratio of the final absolute temperature to the initial absolute temperature?
إجابة
(A)
3:1
6
Two cylinders A and B each contains 30 cm\(^3\) of oxygen and nitrogen respectively at the same temperature and pressure. If there are 5.0 moles of nitrogen, then the mass of oxygen is?
إجابة
(D)
160.0 g
7
A liquid begins to boil when?
إجابة
(C)
its vapour pressure equals the atmosphere pressure
8
A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as?
إجابة
(B)
O+
9
In the oil drop experiment, Millikan determined the?
إجابة
(C)
charge of the electron
10
The ability of ionic solids is generally due to the?
إجابة
(B)
crystal lattice forces
11
Which of the following statements is FALSE about isotopes of the same element?
إجابة
(D)
They have the same atomic number but different umber of elelctrons
12
Helium is often used in observation balloons because it is?
إجابة
(B)
light and non-combustible
13
Deliquescent substances are also?
إجابة
(C)
hygroscopic
14
When plastics and packaging materials made from chloroethene are burnt in the open, the mixture of gases released into the atmosphere is most likely to contain?
إجابة
(C)
hydrogen chloride
15
The difference between colloides and and suspensions is brought out clearly by the fact that while colloids?
إجابة
(D)
do not settle out on standing, suspensions do
16
In general, an increase in temperature increases the solubility of a solute in water because?
إجابة
(D)
most solutes dissolve with absorption of heat
17
Neutralization involves a reaction between H3O+ and?
إجابة
(B)
OH-
18
In the process of silver-plating a metal M, the metal M is the?
إجابة
(D)
cathode and a direct current is used
19
How many moles of copper would be deposited by passing 3F of electricity through a solution of copper (II) tetraoxosulpohate (IV)?
(F = 96 500 C mol-)
إجابة
(C)
1.5
20
2CL-(aq) → CI2(g) + 2e-(aq). The above half-cell reaction occuring at the anode during the electrolysis of dilute ZnCI2 solution is?
إجابة
(B)
oxidation
21
Which of the following is a redox reaction?
إجابة
(B)
2FeBr2(aq) + Br4(aq) → 2FeBr3(aq)
22
Cr\(_2\)O\(_7\)\(^{2-}\)(aq) + 14H\(^+\)(aq) + 6l\(^-\)(aq) → 2Cr\(^{3+}\)(aq) + 3l(g) + 7H\(_2\)O(I).
The change in the oxidation number of oxygen in the equation above is?
إجابة
(A)
0
23
If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?
إجابة
(A)
low temperatures
24
Which of the following processes leads to increase in entropy?
إجابة
(C)
Boiling a sample of water
25
Which of the following equilibria is shifted to the right as a result of an increase in pressure?
إجابة
(B)
2NO2(g) N2O4(g)
26
In the industrial production of hydrogen from natural gas, carbon (IV) oxide produced along with the hydrogen is removed by?
إجابة
(A)
washing with water under pressure
27
Sulphur exists in six forms in the solid state. This property is known as?
إجابة
(B)
allotropy
28
A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?
إجابة
(A)
sulphur (lV) oxide
29
Which of the following ions will give a white precipitate with aqueous NaOH and soluble in excess of the base?
إجابة
(C)
Zn2+
30
In the extraction of iron in the blast furnace, limestone is used to?
إجابة
(D)
remove impurities
31
Which of the following compounds will impart a brick-red colour to a non-luminious bunsen flame?
إجابة
(C)
CaCl2
32
Group 1 A metals are not found free in nature because they?
إجابة
(D)
are very reactive
33
CHCl3 + Cl2 → HCl + CCl4. The reaction above is an example of?
إجابة
(B)
a substitution reaction
34
Which of the following pairs has compounds that are isomers?
إجابة
(A)
Propanal and propanone
35
Aromatic and aliphatic hydrocarbons can be distinguished from each other by the?
إجابة
(C)
action of heat
36
The role of sodium chloride in the preparation of soap is to?
إجابة
(B)
separate the soap from glycerol
37
CxHY + 4O2 → 3CO2 + 2H2O. The hydrocarbon, CxHY, in the reaction above is?
إجابة
(C)
propyne
38
An example of a secondary amine is?
إجابة
(B)
di-butylamine
39
The relatively high boiling points of alkanols are due to?
إجابة
(D)
hydrogen bonding
40
USE THE SECTION OF THE PERIODIC TABLE ABOVE TO ANSWER THIS QUESTION.Which of the indicate an alkali metal and a noble gas respectively?
إجابة
(D)
G and L
41
USE THE SECTION OF THE PERIODIC TABLE ABOVE TO ANSWER THIS QUESTION.Which letter represents a non-metal that is a solid at room temperature?
إجابة
(A)
T
42
The arrangement above can be used for the collection of
إجابة
(D)
nitrogen
43
Use the diagram above to answer this question. The activation energy of the uncatalysed reaction is
إجابة
(A)
X
44
It can be deduced that the rate of the reaction?
إجابة
(B)
for path ll is higher than path l
45
The option above shows the PH changes for the titration of a
