2008 - JAMB Chemistry Past Questions and Answers - page 3
21
Insoluble salts can be prepared by
A
titrating an alkali against an appropriate acid
B
reacting an acid with trioxocarbonatr (IV) salt
C
directing combination of the elements which make up the salt
D
mixing two soluble compounds containing the metallic radical and the acidic radical
correct option: d
Two soluble metal salts react with each other to form one soluble salt and one insoluble salt . Lead nitrate solution and sodium chloride solution react to produce solid lead chloride , leaving soluble sodium nitrate in solution. The lead chloride can be recovered by filtration.
Users' Answers & Comments22
The oxidation state of carbon in HCOOH is
A
-1
B
+2
C
+3
D
zero
correct option: b
HCOOH
O.N of H + O.N of C + 2* O.N of oxygen of
H = 0
1 + X + 2X - 2 + 1 = 0
2 + X -4 = 0
X = 4 - 2 = +2
Users' Answers & CommentsO.N of H + O.N of C + 2* O.N of oxygen of
H = 0
1 + X + 2X - 2 + 1 = 0
2 + X -4 = 0
X = 4 - 2 = +2
23
What is the IUPAC nomenclature of the compound NaCIO?
A
sodium oxochlorate (I)
B
sodium chloro (I) oxide
C
sodium monooxochlorate (II)
D
sodium chloro (I) monoxide
correct option: a
Users' Answers & Comments24
In recharging a lead-acid accumulator, the reaction at the cathode can be represented as
A
Pb2+(aq) + SO2-4(aq) →PbSO4(s)
B
Pb2+(aq) + 2e- →Pb(s)
C
Pb2+(aq) + 2H2O(l) → PbO2(s) + 4H+(aq) + 4e-
D
Pb(s) → Pb2+(aq) + 2e-
correct option: d
Users' Answers & Comments25
If a given quantity of electricity liberates 0.65g of Zn2+, what amount of Hg2+ would be liberated by the same quantity of current?
[Zn = 65, Hg = 201]
[Zn = 65, Hg = 201]
A
1.00g
B
2.10g
C
4.02g
D
8.04g
correct option: b
Users' Answers & Comments26
NH3(g) + HCl(s) → NH4Cl(s)
The entropy change in the system above is
The entropy change in the system above is
A
positive
B
zero
C
negative
D
indeterminate
correct option: c
Users' Answers & Comments27
Which of the following reaction is endothermic?
A
C(s) + O2(g) → CO2(g)
B
CaO(s) + H2O(l) → Ca(OH)2(s)
C
C(s) + H2O(g) → CO(g) + H2(g)
D
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
correct option: c
Users' Answers & Comments28
A catalyst speeds up the rate of chemical reaction by
A
taking part in the reaction
B
increasing the activation energy of the reaction
C
lowering the activation energy of the reaction
D
increasing the heat content
correct option: c
Users' Answers & Comments29
The rate of a reaction usually decrease in the concentration of reactants because
A
kinetic energy decrease
B
temperature increase
C
speed increases
D
reactants collision decrease
correct option: d
Users' Answers & Comments30
The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is
A
oxygen
B
chlorine
C
nitrogen
D
hydrogen
correct option: a
Users' Answers & Comments