2012 - JAMB Chemistry Past Questions and Answers - page 3
21
A major factor considered in selecting a suitable method for preparing a simple salt is its
A
Crystalline from
B
melting point
C
reactivity with dilute acids
D
solubility in water
correct option: d
Users' Answers & Comments23
2Na 2 O 2(s) + 2H 2 O 2(1) → 4 NaOH(s) +O2(s)
The substance that is oxidized in the reaction above is
The substance that is oxidized in the reaction above is
A
2NaO2(s)
B
NaOH(aq)
C
H2O(1)
D
O2(g)
correct option: a
Users' Answers & Comments24
What number of moles of Cu 2+ will be deposited by 360 coulombs of electricity?
[f = 96500 C mol -1]
[f = 96500 C mol -1]
A
5.36 x 10 -4 mole
B
1. 87 x 10 10 -3 mole
C
9. 35 x 10 -4 mole
D
3. 73 x 10 -3
correct option: b
Users' Answers & Comments25
A metal M displaces zinc from ZnCl, solution, solution
This shows that
This shows that
A
electrons flow from zinc to M
B
M is more electropositive than zinc
C
M is more electonegative than zinc
D
zinc is more electropositive than M
correct option: b
Users' Answers & Comments26
CO(g) + H2 O(g) → CO2(g) + H2(g)
Calculate the standard heat change of the reaction above, if the standard enthalpies of formation of CO2(g), H2O(g) and CO(g) and CO(g) in KJ mol -1 are - 394 -242 and - 110 respectively.
Calculate the standard heat change of the reaction above, if the standard enthalpies of formation of CO2(g), H2O(g) and CO(g) and CO(g) in KJ mol -1 are - 394 -242 and - 110 respectively.
A
+ 262 KJ mol -1
B
- 262 KJ mol -1
C
+ 42 KJ mol -1
D
- 42 KJ mol -1
correct option: c
Users' Answers & Comments27
An increase in entropy can best be illustrated by
A
mixing of gases
B
freezing of water
C
the condensation of vapour
D
solidifying candle wax
correct option: a
Users' Answers & Comments28
The highest rate of production of carbon (lV) oxide can be achieved using
A
0.05 mol -3HCI and 5g powdered CaCO3
B
0.05 mol -3HCI and 5g lump CaCO3
C
0.10 mol -3HCI and 5g powdered CaCO3
D
0.025 mol -3HCI and 5g powdered CaCO3
correct option: c
Users' Answers & Comments29
A piece of filter paper moistened with lead (ll) ethanoate solution turns black when the paper is dropped into a gas likely to be
A
sulphur (VI) oxide
B
hydrogen chloride
C
sulphur (VI) oxide
D
hydrogen sulphide
correct option: d
Users' Answers & Comments30
Which of the following gases has a characteristic pungent smell, turns red litmus paper blue and forms dense white fumes with hydrogen chloride gas?
A
N2
B
N2O
C
CI2
D
NH3
correct option: d
Users' Answers & Comments