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