When a solid substance disappears completely as a gas on heating, the substance is said to have undergone
Хариулт
(D)
sublimation
2
A chemical reaction is always associated with
Хариулт
(D)
the formation of new substance
3
If a solution contains 4.9g of tetraoxosulphate (VI) acid, calculate the amount of copper (II) oxide that will react with it
[Cu = 64, O = 16, S = 32, H = 1]
Хариулт
(B)
4.0g
4
What volume of gas is evolved at S.t.p if 2g of calcium trioxocarbonate (IV) is added to a solution of hydrochloric acid?
[Ca = 40, C = 12, O = 16, Cl = 35.5, H = 1 Molar volume of a gas at s.t.p = 22.4 dm\(^3\)
Хариулт
(C)
448 cm3
5
According to charles' law, the volume of a gas becomes zero at
Хариулт
(C)
-273 oC
6
It is difficult to achieve an orderly arrangement of the molecules of a gas because they?
Хариулт
(B)
have little force of attraction between them
7
A given volume of methane diffuses in 20s. How long will it take the same volume of sulphur (IV) oxide to diffuse under the same conditions?
[C = 12, H = 1, S = 32, O = 16
Хариулт
(C)
40s
8
An electron can be added to a halogen atom to form a halide ion with
Хариулт
(D)
8 valence electrons
9
The shape of s-orbitals is
Хариулт
(A)
spherical
10
\(^{226}\)\(_{88}\)Ra → \(^x\)\(_{86}\)Rn + α - particle
What is the value of x in the nuclear reaction above?
Хариулт
(B)
222
11
The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its
Хариулт
(D)
electronegativity
12
Chlorine consisting of two isotopes of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotopes of mass number 37
Хариулт
(B)
25
13
Which of the following mixture of gases is likely to burn in flame?
Хариулт
(A)
neon and hydrogen
14
Hardness of water is caused by the presence of ions of
Хариулт
(B)
calcium and magnesium
15
Pollution of underground water by metal ions is very likely in the soil that has high
Хариулт
(A)
acidity
16
A carcinogenic substance is
Хариулт
(A)
asbestos dust
17
The solubility in moldm\(^{-3}\) of 20g of CuSO\(_4\) dissolved in 100g of water at 180\(^o\)C is
[Cu = 64, S = 32, O =16]
Хариулт
(C)
1.25
18
Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a
Хариулт
(C)
precipitate
19
Which of the following compound is a normal salt?
Хариулт
(D)
Na2CO3
20
What volume of 0.5 mol dm\(^{-3}\) H\(_2\)SO\(_4\) will exactly neutralize 20cm\(^3\) of 0.1 mol dm\(^{-3}\) NaOH solution?
Хариулт
(A)
2.0 cm3
21
The oxidation state of chlorine in HClO\(_4\) is
Хариулт
(D)
+7
22
ZnO(s) + CO(g) → Zn(s) + CO\(_2\)(g)
In the reaction above, Zinc has been
Хариулт
(D)
reduced
23
Which of the following acts as both reducing and oxidizing agent?
Хариулт
(B)
SO2
24
In the electrolysis of brine, the anode is
Хариулт
(D)
carbon
25
The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is
[Ag = 108, 1F = 96500 Cmol-1]
Хариулт
(B)
54.0g
26
2CO(g) + O\(_2\)(g) → 2CO\(_2\)(g)
Given that ΔH[CO]is -110.4 kJmol-1 and ΔH[CO\(_2\)] is -393.0 kJmol-1, the energy change for the reaction above is
Хариулт
(B)
-282.6 kJ
27
Which of the following hydrogen halides has the highest entropy value?
Хариулт
(D)
HI
28
N\(_2\)O\(_4\),(g) ↔ 2NO\(_2\)(g)
In the endothermic reaction above, more product formation will be favoured by
Хариулт
(C)
a decrease in pressure
29
Which of the following shows little or no net reaction when the volume of the system is decreased?
Хариулт
(A)
H2(g) + I2(g) ↔ 2HI(g)
30
The allotrope of carbon used in the decolourization of sugar is
Хариулт
(C)
Charcoal
31
Which of the following gases can be collected by the method of downward delivery?
Хариулт
(A)
Chlorine
32
When steam is passed over red-hot carbon, the substances produced are
Хариулт
(C)
Hydrogen and carbon (II) oxide
33
Sulphur (IV) oxide bleaches by
Хариулт
(A)
Reduction
34
Carbon is tetravalent because
Хариулт
(C)
The 2s and 2p atomic orbitals hybridize
35
Aluminium hydroxide is used in the dyeing industry as a
Хариулт
(C)
Mordant
36
Alloys are best prepared by
Хариулт
(D)
Cooling a molten mixture of the metals
37
Transition metals possess variable oxidation states because they have
Хариулт
(A)
Electrons in the d orbitals
38
Sodium metal is always kept under oil because it
Хариулт
(C)
Reacts vigorously on exposure to air
39
Oxyacetylene flame is used for iron-welding because it
Хариулт
(C)
Evolves a lot of heat when burnt
40
The alkyl group can be represented by the general formula
Хариулт
(A)
CnH2n+1
41
An isomer of C\(_5\)H\(_{12}\) is
Хариулт
(B)
2 – methylbutane
42
A characteristic of the alkane family is
Хариулт
(C)
Substitution reaction
43
Which of these reagents can confirm the presence of a triple bond?
Хариулт
(A)
Bromine water
44
Vulcanization involves the removal of
Хариулт
(C)
the double bond
45
CH\(_3\)COOH(g) → CH\(_4\)(g) + CO\(_2\)(g)
The reaction above is
