2007 - JAMB Chemistry Past Questions and Answers - page 2
11
Which of the following sets of metals dissolves in dilute HCl?
A
Fe, Sn and Cu
B
Mg, Fe and Cu
C
Mg, Sn and Fe
D
Cu, Mg and Sn
correct option: c
Users' Answers & Comments12
If chlorine is bubbled into water and the resulting yellowish-green solution is exposed to bright sunlight for a while, the solution will decompose giving out
A
oxygen and leaving behind aqueous hydrochloric acid
B
chlorine and oxygen
C
oxygen, hydrogen and chlorine
D
oxygen, thereby producing hypochlorous acid
correct option: a
Users' Answers & Comments13
H3PO4(aq) + H2O(l) ↔ H2PO4-(aq) + H3O+(aq)
ΔH = -13kJ at 298K
In the reaction above, an increase in temperature would
ΔH = -13kJ at 298K
In the reaction above, an increase in temperature would
A
slow downthe reverse reaction
B
have no effect on the reaction
C
favour the reverse reaction
D
favour the forward reaction
correct option: c
Users' Answers & Comments14
The reaction that takes place in Daniell cell is
A
direct combination
B
redox
C
double decomposition
D
neutralization
correct option: b
Users' Answers & Comments15
What happens when zinc rod is immersed in copper (II) tetraoxosulphate (VI) solution/
A
The blue colour of the solution disappears
B
Electrons flow from copper to zinc
C
The zinc rod remain undissolved
D
The copper generate more copper ions
correct option: a
Users' Answers & Comments16
C2H4(g) + H2(g) → C2H6(g) ΔH = -137kJ mol-1
The reaction represented above is
The reaction represented above is
A
exothermic
B
spontaneous
C
endothermic
D
in equilibrium
correct option: a
Users' Answers & Comments17
How long would it take to deposit 0.08g of copper from CuCl2 solution by passing a current of 0.5A?
[Cu = 64, F = 96500 C mol-1]
[Cu = 64, F = 96500 C mol-1]
A
6 mins
B
8 mins
C
24 mins
D
48 mins
correct option: b
Cu2+ + 2e → Cu(s)
2 * 96500C deposit 64g of Cu
∴ x quantity of electricity wil deposit 0.08
x = (2 * 96500 * 0.08)/64 =241.25 coulomb.
Q = It
241.25 = 0.5t
t = 241.25/60 = 8 mins
Users' Answers & Comments2 * 96500C deposit 64g of Cu
∴ x quantity of electricity wil deposit 0.08
x = (2 * 96500 * 0.08)/64 =241.25 coulomb.
Q = It
241.25 = 0.5t
t = 241.25/60 = 8 mins
18
tartaric acid is used industrially to
A
make baking powder
B
make fruit juices
C
remove rust
D
dry substance
correct option: a
Users' Answers & Comments19
The salt formed from strong acid and a strong base is
A
complex
B
neutral
C
basic
D
acidic
correct option: b
Users' Answers & Comments20
Dissolving some pellets of NaOH in water would result in
A
a decrease in the free energy of the solution
B
a decrease in the entropy of the solution
C
a lowering of the temperature of te solution
D
an increase in the entropy of the solution
correct option: d
Users' Answers & Comments