Which of the following reactions represents the laboratory preparation of hydrogen?
Answer
(C)
Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g)
3
Which of the following statements best explains cracking ? It is a process
Answer
(B)
in which large hydrocarbon molecules are broken into smaller units
4
120cm3 of hydrogen were sparked with 60cm 3 of oxygen at 110oC. What was the volume of stream produced? The equation for the reaction is 2H2(g) + O2(g) → 2H2O(g)
Answer
(D)
120cm3
5
The earthly impurities in iron ore are removed in the blast furnace by the reaction
Answer
(C)
SiO2 + CaO →CaSiO3
6
Which of the following hydrocarbons is not likely to be present in petrol?
Answer
(A)
C14H30
7
The most suitable method to use when separating an insoluble solid from a liquid is
Answer
(B)
filtration
8
The following are miscible with water except
Answer
(A)
ethylethanoate
9
If 200cm 3 of a gas at s.t.p. has a mass of 0.268g, what is its molar mass? (Molar volume of a gas at s.t.p. = 22.4 dm3)
Answer
(D)
30g
10
How many carbon atoms are there in a benzene ring?
Answer
(C)
6
11
Which of the following gases will bleach moist litmus paper?
Answer
(A)
CI2
12
Given that for the reaction KOH (aq) + HCI(aq) → KCI(aq) + H2O(L) H = - 54 Kj mol-1. What is the quantity of heat involved in the reaction?2NaOH(aq) + H2SO 4(aq) → Na2SO4(aq) + 2H 2O(l)?
Answer
(A)
- 108Kj
13
When an element can exist in two or more forms in the same physical state, the element is said to exhibit
Answer
(C)
allotropy
14
Which of the following carbohydrates does NOT usually occur in the crystalline form?
Answer
(E)
Cellulose
15
Copper can best be purified by
Answer
(C)
electrolyzing a copper (ll) salt solution using the impure copper as the anode
16
Locally produced soap in which wood ash is used as the base is usually soft because the wood ash contains a lot of
Answer
(B)
potassium ions
17
Why is potassium fluoride added to the electrolyte in the extraction of sodium from fused sodium chloride?
Answer
(D)
Potassium fluride reduces the temperature at which sodium chloride fuses
18
The rate of the hydrogen in the reaction Zn(s) + 2HCI (aq) → ZnCI 2(g) + H 2(aq) + H 2(g) can be increased by
Answer
(A)
using Zinc powder instead of Zinc granules
19
Octane number is highest in petrol containing a high proportion of
Answer
(E)
2,2,4-trimethylpentane
20
Given the following half-cell reaction; 2Cl(aq) → CI2(g) + 2e, how many mole of electrons will be required to produce 1.12dm3 of chlorine gas at s.t.p? (Molar volume of a gas at s.t.p. = 22.4dm 3)
Answer
(D)
0.10
21
Which of the following is used extensively in manufacturing photographic chemicals?
Answer
(C)
Silver chloride
22
Given that 1 mole of carbon -12 weighs 12.0g, how many atoms are there in 24.0g magnesium? (C = 12, Mg = 24, NA = 6.02 x 10 23mol-1)
Answer
(B)
1 x 6.02 x10 23
23
If sulphur is dissolved in carbon (IV) sulphide and the solution allowed to evaporate the allotrope of sulphur formed is
Answer
(C)
rhombic sulphur
24
If sulphur is dissolved in carbon (IV) sulphide and the solution is allowed to evaporate, the allotrope of sulphur formed is
Answer
(C)
rhombic sulphur
25
Given that for the reaction. N2(g) + 3H2(g) ⇌ 2NH3(g) ∆H = -92kJ. What is the enthalpy of formation of ammonia from its elements?
Answer
(A)
-46KJ mol -1
26
The following are s-block elements except
Answer
(E)
aluminium
27
Which of the following statements is not true of tin? it
Answer
(D)
combines with copper to form the alloy brass
28
What quantity of copper will be deposited by the same quantity of electricity that deposited 9.0g of aluminum? (A = 27, Cu = 64)
Answer
(B)
32g
29
The electronic configuration of two atoms X and Y are as follows: X - 1s 2 2s 22p 63s 1, Y -1s 22s 22p 63s23p 64s 2 which of the statements below is true of the position of X and Y in the Periodic Table?
Answer
(B)
x belongs to group 1, Y belongs to period 4
30
Which of the following is a condition for a spontaneous reaction?
