2007 - JAMB Chemistry Past Questions & Answers - page 1

1
Trioxonitrate (V) acid is not used for preparing hydrogen gas from metals because it
A
is strongly oxidizing
B
is volatile
C
renders the metal passive
D
forms a layer of oxide on the metal
CORRECT OPTION: a
2
An element used in the production of matches is
A
nitrogen
B
aluminium
C
copper
D
sulphur
CORRECT OPTION: d
3
When calcium oxide is heated with carbon, the oxide will
A
be converted to carbide
B
be converted to the trioxocarbonate (IV) salt
C
decompose to the metal
D
melt,producingg carbon (IV) oxide
CORRECT OPTION: a
4
A solution which on treatment with hydrochloric acid produces a colourless, odourless gas which turns lime water milky is most likely to be a
A
trioxonitrate (V)
B
chloride
C
trioxocarbonate (IV)
D
hydroxide
CORRECT OPTION: c
5
The soft solder used for welding and plumbing is alloy of
A
lead and tin
B
iron and tin
C
lead and zinc
D
iron and zinc
CORRECT OPTION: a
6
The reddish-brown rust on iron roofing sheets consists of
A
Fe3+(H2O)6
B
FeO.H2O
C
Fe2O3.3H2O
D
Fe3O4.2H2O
CORRECT OPTION: c
7
Na2S2O3(aq) + 2HCl(aq) → 2NaCl(aq) + H2O(l)
Which of the following would introduce the greatest increase in the rate of the chemical reaction above?
A
An increase in temperature and decrease in the concentration of the reactant
B
A decrease in the volume and increase in the pressure of the reactant
C
A decrease in the temperature and an incease in the concentration of the reactant
D
An increase in temperature and an increase in the concentration of the reactant
CORRECT OPTION: d
8
The tincture of iodine means iodine dissolved in
A
ethanol
B
bromine chloride
C
chlorine water
D
water
CORRECT OPTION: a
9
Cu2+(aq) + 4NH3(g) ↔ [Cu(NH3)4]2+(aq)
In the reaction above, what is the effect of precipitating Cu2+(aq) as CuS(s)?
A
NH3(g) concentration will decrease
B
more NH3(g)
  • C. The equilibrium will shift to the right
  • D. There will be no effect
  • C
    []
    D
    []
    CORRECT OPTION: c
    10
    Copper and silver metals are commonly use as coin because they are
    A
    easily reduced
    B
    not easily reduced
    C
    easily oxidized
    D
    not easily oxidized
    CORRECT OPTION: d
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