CHEMISTRY CH#10 (VOL-1) ELECTROCHEMISTRY
CHEMISTRY CH#10 (VOL-1) ELECTROCHEMISTRY
1. Which one of the following explains why
copper conducts electricity?
(a) Cu+2 ions move to
the cathode when a current is passed
(b) The bonding electrons in the
crystal lattice move when a potential difference is applied
(c) The crystal lattice breaks
down on applying a potential difference
(d) The electric current causes
the electrons to combine with Cu+2 ions
2. Which one of the following elements has
the same oxidation number in all of its known compounds?
(a) Beryllium (b) Bromine (c) Chlorine (d) Nitrogen
3. In which one of the following reactions,
hydrogen behave as an oxidizing agent?
(a)
(b) 
(c) 
(d)
(b) (c) (d)
4. What change in oxidatioln state takes
place in nitrogen when copper reacts with HNO3 according to equation?
(a)
+5 to -2 (b) +5 to +4 (c) +5 to 0 (d) 0 to -4
5. When Aluminum electrode is coupled
copper electrode in a galvanic cell
(a)
Reduction takes place at copper electrode (b)
Oxidation takes place at copper electrode
(c) Reduction takes place at aluminum
electrode (d) Both b and c
6. In K2MnO4,
oxidation number of Mn is
(a) +7 (b) +6 (c) +5 (d) +4
7. Which statement is correct about
standard hydrogen electrode?
(a) 1.0M HCl solution is used (b) H2 gas at 1 atm
pressure is present
(c) Platinum electrode is used (d) All of the
above
8. Electrolysis is a process in which a
chemical reaction takes place at the expense of
(a)
Chemical energy (b) Electrical
energy (c) Heat energy (d) None of these
9. Standard hydrogen electrode has an
arbitrarily fixed potential
(a)
0.00 volt (b) 1.00 volt (c) 0.10 volt (d) None of these
10.
The oxidation number of chromium in K2Cr2O7 is
(a) 14 (b)
12 (c) 6 (d) None of these
11. In
the reaction
(a) Fe is reduced (b) Fe is
oxidized (c) Cl2 is
oxidized (d) None of these happen
12. When
fused PbBr2 is electrolyzed
(a) Bromine appears at the cathode (b)
Lead is deposited at the cathode
(c) Lead appear at the anode (d) None of
these happen
13.
Which one of the following represents reduction?
(a) 
(b)
(b)
(c) 
(d)
(d)
14. In
the given equation (
)
)
Which one of the following is the correct change in oxidation state of
hydrogen?
(a) 0 to +1 (b) 0 to +2 (c) +1 to +2 (d) +1 to 0
15.
Which one of the following is correct definition of oxidation?
(a) Addition of oxygen, addition of
hydrogen and addition of electrons
(b) Addition of oxygen, removal of
hydrogen and addition of electrons
(c) Addition of oxygen, removal of hydrogen
and removal of electrons
16.
Which statement is correct about electrolysis of molten NaCl?
(a) Oxidation take place at cathode (b)
Cl2 gas is formed at anode
(c) Reduction occur at anode (d) H2
gas is formed at cathode
17.
Oxidation state of oxygen is OF2 is
(a) 0 (b) +1 (c)
-2 (d)
+2
18. In
case of superoxides, the oxidation number of oxygen is
(a) 0 (b) +1 (c) 
(d)
-1
(d)
-1
19.
A half reaction is defined as
(a)
Occurs at one electrode (b)
Goes only half way to completion
(c) Involves only half a mole of
electrolyte (d) Is always a
cathode reaction
20. A cell which produces electrical
current by an oxidation reduction reaction is known as
(a)
Voltaic cell (b) Standard
cell (c) Reversible cell (d) Electrolytic cell
21. The
cell in which a non spontaneous redox reaction takes place as a result of
electricity is known as
(a)
Voltaic cell (b) Denial cell (c) Dry cell (d)
Electrolytic cell
22. Sodium
can be obtained by
(a) Electrolysis of molten sodium chloride (b) Electrolysis of aqueous solution chloride
(c) By heating NaCl and water at 1000C (d) Electrolysis of acidified
water
23.
What are the products of electrolysis of aqueous sodium chloride at the two
electrodes?
(a) Chlorine at anode and hydrogen at
cathode (b) Chlorine at anode and
oxygen at cathode
(c) Chlorine at anode and sodium at
cathode (d) Hydrogen at anode and
chlorine at cathode
24. Which statement is incorrect about the
given cell representation?
(a) Zinc rod act as cathode (b)
Copper rod act as cathode
(c) Zinc rod have negative sign (b) Copper rod
have positive sign
25.
What is the oxidation state of sulphur in SO2-3?
(a) -4 (b) -2 (c)
+2 (d) +4
26.
Which one of the following formulae contains nitrogen with an oxidation state
of +5?
(a) NH4+ (b) NH3 (c) HNO3 (d) NO2
28. Which one of the followings
correctly describes the process occurring at the electrodes when molten NaCl is
electrolyzed?
(a) Oxidation at anode, reduction at cathode (b) Oxidation at cathode, reduction at anode
(b) No reaction at anode, reduction at
cathode (d) No reaction at
cathode, oxidation at anode
29. In
the given equation underlined element is (
)
)
(a) Oxidized (b) Reduced
(c) Neither oxidized nor reduced
30.
The function of salt bridge is
(a) To reduce the temperature (b) To maintain
electrical neutrality
(c) To increase the movement of ions (d) To increase the e.m.f
of cell
31. In
lead accumulator (storage battery) cathode is made of
(a) Pb (b) Pb coated with PbO2 (c) PbSO4 (d) Mixture of Pb and PbO2-
32.
During electrolysis, the reaction that takes place at cathode
(a) Oxidation (b) Reduction (c) Both (d) None
33. When
aqueous NaCl is electrolyzed, which of the following ions gets discharged at
anode
(a) Cl- (b) OH-
34.
In an electrolytic cell, the electrons flow from
(a) Cathode to anode (b)
Anode to cathode
(c) From cathode to anode or opposite,
depending upon the nature of electrolyte (d) Does not flow
35. A
primary cell is that
(a) Which is not chargeable
(b)
Which is chargeable
(c) In which one electrode used in
standard hydrogen electrode (d) Whose
potential difference is zero
36.
A secondary cell is that
(a) Which is not chargeable
(b)
Which is chargeable
(c) In which one electron is SHE (d) Whose potential
difference is zero
CHAPTER # 10 (ANSWER
KEY)
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1
|
b
|
11
|
b
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21
|
d
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31
|
b
|
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2
|
a
|
12
|
b
|
22
|
b
|
32
|
b
|
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3
|
c
|
13
|
b
|
23
|
a
|
33
|
a
|
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4
|
b
|
14
|
d
|
24
|
a
|
34
|
b
|
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5
|
a
|
15
|
c
|
25
|
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35
|
a
|
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6
|
b
|
16
|
b
|
26
|
d
|
36
|
b
|
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7
|
d
|
17
|
d
|
27
|
c
|
|
|
|
8
|
b
|
18
|
c
|
28
|
a
|
|
|
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9
|
a
|
19
|
a
|
29
|
b
|
|
|
|
10
|
c
|
20
|
a
|
30
|
b
|
|
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