Chromatography is used to separate components of mixtures which differ in their rates of?
Απάντηση
(B)
migration
2
Which of the following is a example of a chemical change?
Απάντηση
(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\(^{23}\) )
Απάντηση
(B)
6.02 x 1022
4
What volume of oxygen will remain after reacting 8cm\(^3\) of hydrogen with 20cm\(^3\) of oxygen?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(D)
160.0 g
7
A liquid begins to boil when?
Απάντηση
(C)
its vapour pressure equals the atmosphere pressure
8
A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as?
Απάντηση
(B)
O+
9
In the oil drop experiment, Millikan determined the?
Απάντηση
(C)
charge of the electron
10
The ability of ionic solids is generally due to the?
Απάντηση
(B)
crystal lattice forces
11
Which of the following statements is FALSE about isotopes of the same element?
Απάντηση
(D)
They have the same atomic number but different umber of elelctrons
12
Helium is often used in observation balloons because it is?
Απάντηση
(B)
light and non-combustible
13
Deliquescent substances are also?
Απάντηση
(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?
Απάντηση
(C)
hydrogen chloride
15
The difference between colloides and and suspensions is brought out clearly by the fact that while colloids?
Απάντηση
(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?
Απάντηση
(D)
most solutes dissolve with absorption of heat
17
Neutralization involves a reaction between H3O+ and?
Απάντηση
(B)
OH-
18
In the process of silver-plating a metal M, the metal M is the?
Απάντηση
(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-)
Απάντηση
(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?
Απάντηση
(B)
oxidation
21
Which of the following is a redox reaction?
Απάντηση
(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?
Απάντηση
(A)
0
23
If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?
Απάντηση
(A)
low temperatures
24
Which of the following processes leads to increase in entropy?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(A)
washing with water under pressure
27
Sulphur exists in six forms in the solid state. This property is known as?
Απάντηση
(B)
allotropy
28
A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?
Απάντηση
(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?
Απάντηση
(C)
Zn2+
30
In the extraction of iron in the blast furnace, limestone is used to?
Απάντηση
(D)
remove impurities
31
Which of the following compounds will impart a brick-red colour to a non-luminious bunsen flame?
Απάντηση
(C)
CaCl2
32
Group 1 A metals are not found free in nature because they?
Απάντηση
(D)
are very reactive
33
CHCl3 + Cl2 → HCl + CCl4. The reaction above is an example of?
Απάντηση
(B)
a substitution reaction
34
Which of the following pairs has compounds that are isomers?
Απάντηση
(A)
Propanal and propanone
35
Aromatic and aliphatic hydrocarbons can be distinguished from each other by the?
Απάντηση
(C)
action of heat
36
The role of sodium chloride in the preparation of soap is to?
Απάντηση
(B)
separate the soap from glycerol
37
CxHY + 4O2 → 3CO2 + 2H2O. The hydrocarbon, CxHY, in the reaction above is?
Απάντηση
(C)
propyne
38
An example of a secondary amine is?
Απάντηση
(B)
di-butylamine
39
The relatively high boiling points of alkanols are due to?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(A)
T
42
The arrangement above can be used for the collection of
Απάντηση
(D)
nitrogen
43
Use the diagram above to answer this question. The activation energy of the uncatalysed reaction is
Απάντηση
(A)
X
44
It can be deduced that the rate of the reaction?
Απάντηση
(B)
for path ll is higher than path l
45
The option above shows the PH changes for the titration of a
