ELECTROCHEMISTRY WORKSHEET FOR JEE

Transcription

ELECTROCHEMISTRY
WORKSHEET FOR
JEE-ADVANCE/AIIMS
1.
2.
3.
4.
5.
6.
1
The standard electrode potential values of the element A, B and C are 0.68, −2.50
and −0.50 V respectively. The order of their reducing power is :
(a) A > B > C
(b) A > C >B
(c) C > B > A
(d) B > C > A
The following four colourless salt solutions are placed in separate test tubes and
a strip of copper is placed in each. Which solution finally turns blue ?
The oxidation potentials of Zn, Ag, Cd, Pb and Cu are +0.76, -0.80, +0.40, +0.13
and −0.34 respectively
(a) Zn(NO3)2
(b) AgNO3
(d) Pb(NO3)2
(c) Cd(NO3)2
+
For the electrochemical cell, M | M || X | X, E°(M+/M)=0.44 V and E°(X/X )
=0.33V. From this data, one can deduce that
(a) M + X → M+ + X is the spontaneous reaction
(b) M+ + X → M + X is the spontaneous reaction
(c) Ecell = 0.77 V
(d) Ecell = −0.77 V
The standard electrode potentials of Zn2+/Zn and Ag+/Ag are – 0.763 V and
+0.799 V respectively. The standard potential of the cell is…
[KCET 1993]
(a) 1.56 V
(b) 0.036 V
(c) –1.562V
(d) 0.799 V
Which of the following metal does not react with the solution of copper
sulphate…?
[CPMT 1999]
(a) Mg
(b) Fe
(c) Zn
(d) Ag
The standard oxidation potential of zinc and silver in water at 298 K are
Zn(s) →Zn2+ + 2e– ; E = 0.76 V
Ag(s) → Ag+ + e– ; E = – 0.80 V
Which of the following reactions actually take place
[KCET 2003]
+
++
(a) Zn(s) + 2Ag (aq) → Zn (aq) + 2Ag(s)
(b) Zn++(aq) + 2Ag(s) → Zn (s) + 2 Ag+(aq)
(c) Zn (s) + Ag(s) → Zn++ (aq) + Ag+(aq)
(d) Zn++(aq) + Ag+(aq) → Zn (s) + Ag(s)
Electrochemistry-Worksheet JEE Advance/AIIMS
7.
8.
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11.
12.
13.
14.
2
Consider the reaction Mn+(aq) + ne– → M(s). The standard reduction potential
values of the elements M1, M2 and M3 are – 0.34 V, – 3.05 V and –1.66 V
respectively. The order of their reducing power will be
(a) M1 > M2 > M3
(b) M3 > M2 > M1
(c) M1 > M3 > M2
(d) M2 > M3 > M1
Four alkali metals A, B, C and D are having respectively standard electrode
potential as –3.05, –1.66, –0.40 and 0.80. Which one will be the most reactive…
[CPMT 1983; MP PET/PMT 1988; MNR 1993; UPSEAT 2002]
(a) A
(b) B
(c) C
(d) D
Which one of the following reaction is not possible…
[MP PMT 1991]
(a) Fe + H2SO4 →FeSO4 + H2
(b) Cu + 2AgNO3 →Cu (NO3)2 + 2Ag
(c) 2KBr + I2 →2KI + Br2
(d) CuO + H2 →Cu + H2O
When a rod of metal A is dipped in an aqueous solution of metal B
(concentration of B2+ ion being 1M) at 25 0C, the standard electrode potentials are
A2+/A = – 0.76 volts, B2+/B = + 0.34 volts.
[KCET 1992]
(a) A will gradually dissolve
(b) B will deposit on A
(c) No reaction will occur
(d) Water will decompose into H2 and O2
The reaction Zn2+ + 2e–→Zn has a standard potential of –0.76 V. This means…
[KCET 1992]
(a) Zn can’t replace hydrogen from acids (b) Zn is a reducing agent
(c) Zn is an oxidising agent
(d) Zn2+ is a reducing agent
For a spontaneous reaction the ∆G, equilibrium constant (K) and E0Cell will be
respectively.
[AIEEE 2005]
(a) –ve, > 1, + ve
(b) +ve, > 1, –ve
(c) –ve, < 1, – ve
(d) –ve, > 1, – ve
The reference electrode is made form which of the following…
[MP PET/PMT 1988; MP PMT 2002]
(a) ZnCl2
(b) CuSO4
(c) Hg2Cl2
(d) HgCl2
The standard reduction potential for Li+ / Li ; Zn2+/ Zn; H+/H2 and Ag+ / Ag is –
3.05, –0.762, 0.00 and +0.80V. Which of the following has highest reducing
capacity…?
[MP PMT 1992]
(a) Ag
(b) H2
(c) Zn
(d) Li
15.
16.
17.
18.
19.
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21.
22.
23.
24.
When electric current is passed through a cell having an electrolyte, the positive
ions move towards the cathode and the negative ions towards the anode. If the
cathode is pulled out of the solution.
[AIIMS 1980]
(a) The positive and negative ions will move towards the anode
(b) The positive ions will start moving towards the anode, the negative ions will
stop moving
(c) The negative ions will continue to move towards the anode and the positive
ions will stop moving
(d) The positive and negative ions will start moving randomly
In Cu — Zn cell
[BHU 1981]
(a) Reduction occurs at the copper cathode
(b) Oxidation occurs at the copper cathode
(c) Reduction occurs at the anode
(d) Chemical energy is converted to light energy
For cell reaction, Zn + Cu2+ → Zn2+ + Cu, cell representation is…
[BCECE 2005]
(a) Zn | Zn2+ ||Cu2+ | Cu
(b) Cu | Cu2+ ||Zn2+ | Zn
(c) Cu | Zn2+ ||Zn | Cu2+
(d) Cu2+| Zn || Zn2+ |Cu
Which one is not called an anode reaction from the following…
1
(a) Cl– →
Cl2 + e–
(b) Cu →Cu++ + 2e–
2
(c) Hg+ →Hg++ + e–
(d) Zn2+ + 2e– → Zn
A cell from the following which converts electrical energy into chemical energy
(a) Dry cell
(b) Electrochemical cell
(c) Electrolytic cell
(d) None of these
2+
2+
In the cell Zn | Zn ||Cu | Cu, the negative electrode is…
[MP PMT 1995]
(a) Cu
(b) Cu2+
(c) Zn
(d) Zn2+
The standard cell potential of Zn | Zn2+(aq) || Cu2+(aq) |Cu cell is 1.10 V. The
maximum work obtained by this cell will…
[MP PET 2002]
(a) 106.15 kJ
(b) –212.30 kJ
(c) – 318.45 kJ
(d) –424.60kJ
Consider the Galvanic cell Zn | ZnSO 4 || CuSO4 |Cu the reaction at cathode is…
[AMU 2000]
2+
–
(a) Zn +2 e →Zn
(b) Cu2+ +2 e– → Cu
(c) Cu2+ +Zn → Cu + Zn2+
(d) Zn2+ +Cu → Zn + Cu2+
+
+2
The cell reaction Cu + 2Ag →Cu + Ag is best represented by…
[AMU 2000]
2+
+
(a) Cu(s) |Cu (aq)|| Ag (aq) |Ag(s)
(b) Pt |Cu+2|| Ag+(aq) |Ag(s)
2+
(c) Cu | Cu ||Pt | Ag
(d) None of the above representations
2+
2+
Zn( g) |Zn ( aq ) || Cu ( aq ) |Cu( s ) is…
[Kerala (Engg.) 2002]
(anode )
(a) Weston cell
(c) Calomel cell
3
(cathode)
(b) Daniel cell
(d) Faraday cell
(e) Standard cell
25.
Saturated solution of KNO3 is used to make ‘salt-bridge’ because…
[IIT Screening 2002]
–
(a) Velocity of K+ is greater than that of NO3
–
(b) Velocity of NO3 is greater than that of K+
–
26.
27.
28.
29.
30.
31.
32.
4
(c) Velocity of K+ and NO3 are nearly the same
(d) KNO3 is highly soluble in water
In balancing the half reaction S2O32– → S(s) the number of electrons that must be
[DPMT 2000]
added is…
(a) 4 on the left
(b) 3 on the right
(c) 2 on the left
(d) 2 on the right
Which one of the following statement is true for a electrochemical cell…
[Pb. PMT 1999; KCET 1999]
(a) H2 is cathode and Cu is anode
(b) H2 is anode and Cu is cathode
(c) Reduction occurs at H2 electrode
(d) Oxidation occurs at Cu electrode
Which of the following statements about galvanic cell is incorrect…?
[JIPMER 1997]
(a) Anode is positive
(b) Oxidation occurs at the electrode with lower reduction potential
(c) Cathode is positive
(d) Reduction occurs at cathode
The position of some metals in the electrochemical series in decreasing
electropositive character is given as Mg >Al > Zn > Cu > Ag. What will happen, if
a copper spoon is used to stir a solution of aluminium nitrate
(a) The spoon will get coated with Al
(b) An alloy of Cu and Al is formed
(c) The solution becomes blue
(d) There is no reaction
Which of the following is not used to construct salt bridge…?
[MP PET 2003]
(a) CH3COOK
(b) KCl
(c) NH4NO3
(d) KNO3
The hydrogen electrode is dipped in a solution of pH = 3 at 25 °C. The oxidation
potential of the cell would be (the value of 2.303RT/F is 0.059 V)…
[KCET 1993, 2005]
(a) 0.177 V
(b) – 0.177 V
(c) 0.087 V
(d) 0.059 V
Beryllium is placed above magnesium in the second group. Beryllium dust,
therefore when added to MgCl2 solution will…
[CPMT 1977]
(a) Have no effect
(b) Precipitate Mg metal
(c) Precipitate MgO
(d) Lead of dissolution of Be metal
33.
34.
35.
36.
The name of equation showing relation between electrode potential (E),
standard electrode potential (E0) and concentration of ions in solution is
(a) Kohlrausch’s equation
(b) Nernst’s equation
(c) Ohm’s equation
(d) Faraday’s equation
The correct representation of Nernst’s equation is
0.0591
(a) EM n+ /M = E0 M n+ / M +
log ( M n + )
n
0.0591
(b) EM n+ /M = E0 M n+ / M −
log ( M n + )
n
n
(c) EM n+ /M = E0 M n+ / M +
log ( M n + )
0.0591
(d) None of the above
Four alkali metals A, B, C and D are having respectively standard electrode
potential as – 3.05, –1.66, – 0.40 and 0.80. Which one will be the most reactive
[CPMT 1983; MP PET/PMT 1988; MNR 1993; UPSEAT 2002]
(a) A
(b) B
(c) C
(d) D
What is the correct Nernst equation for reaction taking place in the following cell
[Gujarat CET 2007]
2+
–
Mg(s) | Mg (aq) || Cl (aq)|Cl2(g) (1 atm)/Pt
2
(a) Ecell = E
0
cell
Cl − 
0.0592
−
× log
n
 Mg 2 + 
2+
(b) Ecell = E
0
cell
 Mg 
0.0592
−
× log  − 
n
Cl 
2
0.0592
× log  Mg 2 +  Cl − 
n
 Mg 2 + 
0.0592
0
(d) Ecell = Ecell
−
× log 
2
n
Cl − 
E0 values of Mg2+/ Mg is – 2.37 V, of Zn2+ / Zn is – 0.76V and Fe2+ /Fe is
– 0.44V. Which of the following statements is correct…?
[EAMCET 1989]
(a) Zn will reduce Fe2+
(b) Zn will reduce Mg2+
(c) Mg oxidises Fe
(d) Zn oxidises Fe
2+
The standard reduction potential for Fe / Fe and Sn2+ / Sn electrodes are –0.44
and –0.14 volt respectively. For the given cell reaction Fe2+ + Sn →Fe + Sn2+, the
standard EMF is
[IIT Screening 1990 MP PMT 2003]
(a) +0.30 V
(b) – 0.58 V
(c) +0.58 V
(d) –0.30 V
0
0
When EAg+ / Ag = 0.8 volt and EZn2+ /Zn = − 0.76 volt. Which of the following is
0
(c) Ecell = Ecell
−
37.
38.
39.
correct…?
(a) Ag+ can be reduced by H2
(c) Zn2+ can be reduced by H2
5
[MP PMT 1994]
(b) Ag can oxidize H2 into H+
(d) Ag can reduce Zn2+ ion
40.
41.
42.
43.
44.
45.
46.
47.
6
Adding powdered lead and iron to a solution that is 1.0 M in both Pb2+ and Fe2+
ions, would result a reaction, in which…(E° Pb2+/Pb = − 0.126 V and E° Fe2+/Fe
= −0.440 V)
[CPMT 1987]
2+
(a) More iron andPb ions are formed
(b) More lead and Fe2+ ions are formed
(c) Concentration of both Pb2+and Fe2+ ions increases
(d) There is no net change
When compared to ∆G ° for the formation of Al2O3, the ∆G ° for the formation of
Cr2O3 is…
[KCET 2008]
(a) Same
(b) Unpredicted
(c) Higher
(d) Lower
Reduction potential of four elements P, Q, R, S is –2.90, +0.34, +1.20 and
–0.76. Reactivity decreases in the order …
[MP PET 1989; UPSEAT 2001]
(a) P > Q > R > S
(b) Q > P > R > S
(c) R > Q > S > P
(d) P > S > Q > R
Standard electrode potential of Ag+/ Ag and Cu+/Cu is +0.80V and + 0.34 V
respectively. These electrodes are joint together by salt bridge if…
[AMU 2002]
(a) Silver electrode work like anode, then E0cell is – 0.34 V
(b) Copper electrode work like anode, then E0cell is + 0.46 V
(c) Silver electrode work like cathode, then E0cell is – 0.34 V
(d) Silver electrode work like anode, then E0cell will be + 1.14 V
The reaction is spontaneous if the cell potential is…
[MP PET 1999]
(a) Positive
(b) Negative
(c) Zero
(d) Infinte
The equilibrium constant of the following redox reaction at 298 K is 1 × 108 ; 2Fe3+(aq) +
2I– (aq) ↔ 2Fe2+(aq) + I2(s). If the standard reduction potential of iodine becoming iodide
is + 0.54 V, what is the standard reduction potential of Fe3+/ Fe2+.
[Kerala PMT 2008]
(a) + 1.006V
(b) – 1.006 V
(c) + 0.77 V
(d) – 0. 77 V
(e) – 0.652 V
Iron displaces copper from its salt solution, because…
[MP PMT 1996]
(a) Atomic number of iron is less than that of copper
(b) The standard reduction potential of iron is less than that of copper
(c) The standard reduction potential of iron is more than that of copper
(d) The iron salt is more soluble in water than the copper salt.
(i) Copper metal dissolves in 1M silver nitrate solution and crystals of silver
metal get deposited
(ii) Silver metal does not react with 1M zinc nitrate solution
(iii) Zinc metal dissolves in 1M copper sulphate solution and copper metal gets
deposited
Hence the order of decreasing strength of the three metals as reducing agents will be
48.
49.
(a) Cu > Ag > Zn
(b) Ag > Cu > Zn
(c) Zn > Cu > Ag
(d) Cu > Zn > Ag
Calculate
standard
free
energy
change
for
the
reaction
1
1
1
Cu ( s ) + Cl2 ( g ) Cu 2 + + Cl − taking place at 25 0C in a cell whose standard e.m.f.
2
2
2
is 1.02 volts …
[MP PMT 1997]
(a) –98430 J
(b) 98430 J
(c) 96500 J
(d) – 49215 J
0
0
Given EFe3+ /Fe = − 0.036V , EFe2+ /Fe = − 0.439V . The value of standard electrode
potential for the change Fe(3aq+ ) + e − → Fe 2 + ( aq ) will be…
50.
51.
52.
53.
54.
7
[AIEEE 2009]
(a) – 0.072 V
(b) 0.385 V
(c) 0.770 V
(d) −0.270 V
Which one of the following statements is correct…?
[MP PET 1997]
(a) The oxidation number of oxygen in KO2 is zero
(b) The specific conductance of an electrolyte solution decreases with increase in
dilution
(c) Sn2+ oxidises Fe3+
(d) Zn/ZnSO4 is a reference electrode
In infinite dilutions, the equivalent conductances of Ba2+ and Cl– are 127 and 76
ohm–1 cm–1 equt–1. The equivalent conductivity of BaCl2 at indefinite dilution is…
[CBSE 2000]
(a) 101.5
(b) 139. 5
(c) 203.5
(d) 279.5
The factor which is not affecting the conductivity of any solution is
(a) Dilution
(b) Nature of electrolyte
(c) Temperature
(d) None of these
The conductivity of strong electrolyte is…
[KCET 1993; CPMT 2003]
(a) Increase on dilution slightly
(b) Decrease on dilution
(c) Does not change with dilution
(d) Depend upon density of electrolytes itself
If X is the specific resistance of the solution and M is the molarity of the solution,
the molar conductivity of the solution is given by…
[Kurukshetra CEE 2002]
1000X
1000
(a)
(b)
M
MX
1000M
MX
(c)
(d)
X
1000
55.
56.
57.
58.
59.
60.
61.
62.
8
If one end of a piece of a metal is heated, the other end becomes hot after some
time. This is due to …
[CBSE PMT 1995]
(a) Energised electrons moving to the other part of the metal
(b) Resistance of the metal
(c) Mobility of atoms in the metal
(d) Minor perturbation in the energy of atoms
Conductivity of a solution is directly proportional to…
[KCET 1984]
(a) Dilution
(b) Number of ions
(c) Current density
(d) Volume of the solution
The increase in equivalent conductance of an electrolyte solution with dilution is
due to the increase in…
[MP PMT 1996]
(a) Ionic attraction
(b) Molecular attraction
(c) Degree of association of the electrolyte
(d) Degree of ionization of the electrolyte
Which of the following conducts electricity…?
[AFMC 1995]
(a) Fused NaCl
(b) CO2
(c) Br2
(d) Si
It has been observed that gaseous hydrogen chloride is a very poor conductor of
electricity but a solution of hydrogen chloride gas in water is a good conductor
of electricity. This is due to the fact that
(a) Water is good conductor of electricity
(b) Hydrogen chloride gas in water solution ionizes
(c) A gas is non-conductor but a liquid conducts electricity
(d) Gas does not obey Ohm’s law whereas solution does
Electrolytic conduction differs from metallic conduction in that in the case of
electrolytic conduction….
[KCET 1987; Bihar CEE 1992]
(a) The resistance increases with increasing temperature
(b) The resistance decreases with increasing temperature
(c) The flow of current does not generate heat
(d) The resistance is independent of the length of the conductor.
The electrolytic conductance is a direct measure of…
[KCET 1990; CPMT 2003]
(a) Resistance
(b) Potential
(c) Concentration
(d) Dissociation
What is the effect of dilution on the equivalent conductance of strong
electrolyte…
[RPMT 2006]
(a) Decrease on dilution
(b) Remains unchanged
(c) Increase on dilution
63.
64.
65.
66.
67.
68.
69.
70.
71.
9
Which of the following statements is not applicable to electrolytic conductors…?
[AIIMS 1991]
(a) New products show up at the electrodes
(b) Ions are responsible for carrying the current
(c) Show a positive temperature coefficient for conductance
(d) A single stream of electrons flows from cathode to anode
Which one is not a conductor of electricity…
[RPET 1999]
(a) NaCl (aqueous)
(b) NaCl (solid)
(c) NaCl (molten)
(d) Ag metal
The molar conductivities of KCl, NaCl and KNO3 are 152, 128 and 111 S cm–1 mol–1
respectively. What is the molar conductivity of NaNO3…
[VITEEE 2008]
2
–1
(a) 101 S cm mol
(b) 87 S cm2 mol–1
(c) – 101 S cm2 mol–1
(d) – 391 S cm2 mol–1
Which of the following is a poor conductor of electricity…?
[EAMCET 1992]
(a) CH3COONa
(b) C2H5OH
(c) NaCl
(d) KOH
Given l / a = 0.5 cm–1. R = 50 ohm, N = 1.0. The equivalent conductance of the
electrolytic cell is…
[Orissa JEE 2005]
–1
2
–1
(a) 10 ohm cm gm eq
(b) 20 ohm–1 cm2 gm eq–1
–1
2
–1
(c) 300 ohm cm gm eq
(d) 100 ohm–1 cm2 gm eq–1
If equivalent conductance of 1M benzoic acid is 12.8 ohm–1cm2 and if the
conductance of benzoate ion and H+ ion are 42 and 288.42 ohm–1cm2 respectively.
Its degree of dissociation is…
[DPMT 2005]
(a) 39%
(b) 3.9%
(c) 0.35%
(d) 0.039%
–1
The unit ohm is used for …
[J & K 2005]
(a) Molar conductivity
(b) Equivalent conductivity
(c) Specific conductivity
(d) Conductivity
What a solution of an electrolyte is heated the conductance of the solution…
[KCET 1991]
(a) Increases because of the electrolyte conduct better
(b) Decrease because of the increased heat
(c) Decreases because of the dissociation of the electrolyte is suppressed
(d) Increases because the electrolyte is dissociated more
What is the % dissociation of CH3COOH, if equivalent conductivity at this
dilution and at infinite dilution is 148 and 398 S cm2/mol respectively…
[AMU 2006]
(a) 37.18%
(b) 47%
(c) 48.78%
(d) 10.8%
72.
73.
Molar conductance of electrolytic solution Λm is …
[DCE 2007]
(a) ∝ l
(b) ∝ (1/A)
(c) ∝ (1/C)
(d) ∝ ( C )
At 25 0C, the molar conductance at infinite dilution for the strong electrolytes
NaOH, NaCl and BaCl2 are 248 × 10–4, 126 × 10–4 and 280 × 10−4 Sm2mol–1
respectively. λm0 Ba ( OH ) 2 in S m2mol–1 is …
10–4
(a) 52.4 ×
(c) 402 × 10–4
74.
75.
76.
77.
78.
79.
80.
10
[EAMCET 2009]
(b) 524 × 10–4
(d) 262 × 10–4
M
solution of a weak monobasic acid is 8.0 mhos
32
cm2 and at infinite dilution is 400 mhos cm2. The dissociation constant of this acid
is…
[CBSE PMT 2009]
(a) 1.25 × 10–5
(b) 1.25 × 10–6
(c) 6.25 × 10–4
(d) 1.25 × 10–4
The correct expression in SI system relating the equivalent conductance (λC),
specific conductance ( κ ) and equivalent concentration (C) is… Where C is the
number of gm equivalents in one litre of the solution.
[J & K 2009]
κ
1000
(a) λC =
(b) λC = κ ×
C
C
−3
κ × 10
κ × 10 −6
(c) λC =
(d) λC =
C
C
–1
The specific conductance of a solution is 0.2 ohm cm–1 and conductivity is 0.04
ohm–1. The cell constant would be…
[RPET 1999]
–1
(a) 1 cm
(b) 0 cm–1
(d) 0.2 cm–1
(c) 5 cm–1
If the conductance and specific conductance of a solution is one then its cell
constant would be…
[RPET 1999]
(a) 1
(b) Zero
(c) 0.5
(d) 4
The molar conductances of NaCl, HCl and CH3COONa at infinite dilution are
126.45, 426.16 and 91 ohm–1 cm2 mol–1 respectively. The molar conductance of
CH3COOH at infinite dilution is…
[CBSE PMT 1997; DCE 2009]
–1
2
–1
(a) 201. 28 ohm cm mol
(b) 390.71 ohm–1 cm2 mol–1
(c) 698.28 ohm–1 cm2 mol–1
(d) 540.48 ohm–1 cm2 mol–1
The electrodes of a conductivity cell are 3 cm apart and have a cross-sectional
area of 4 cm2. The cell constant of the cell (in cm–1) is
(a) 4 × 3
(b) 4 / 3
(c) 3 / 4
(d) 9 / 4
In the electrolysis of aqueous solution of CuSO4 using copper electrodes, the
process that takes place at the anode is [J & K 2009]
(a) SO42– → SO4 + 2e–
(b) Cu → Cu + + e –
–
–
(c) 2OH → H2O + ½ O2 +2e
(d) Cu → Cu2+ + 2e–
The equivalent conductance of
81.
82.
83.
84.
85.
86.
87.
88.
89.
90.
11
Strong electrolytes are those which...
[MNR 1983; AMU 1983, 84]
(a) Dissolve readily in water
(b) Conduct electricity
(c) Dissociate into ions at high dilution
(d) Completely dissociate into ions at all dilutions
Electrolyte can conduct electricity because
(a) Their molecules contain unpaired electrons, which are mobile
(b) Their molecules contain loosely held electrons which get free under
the influence of voltage
(c) The molecules break up into ions when a voltage is applied
(d) The molecules are broken up into ions when the electrolyte is fused or
is dissolved in the solvent
Which one of the following metals could not be obtained on electrolysis of
aqueous solution of its salts…?
[IIT 1990]
(a) Ag
(b) Mg
(c) Cu
(d) Cr
Which of the following aqueous solution will conduct an electric current quite
well…?
[MP PMT 1987]
(a) Glycerol
(b) HCl
(c) Sugar
(d) Pure water
On the electrolysis of aqueous solution of sodium sulphate, on cathode we get…
[MP PMT 1992, 2002]
(a) Na
(b) H2
(c) SO2
(d) SO3
Electrolysis involves oxidation and reduction respectively at…
[AMU 1983, MH CET 2001]
(a) Anode and cathode
(b) Cathode and anode
(c) At both the electrodes
Which of the following compounds will not undergo decomposition on passing
electricity through aqueous solution…? [AMU 1982, 83; MP PET 2001]
(a) Sugar
(b) Sodium Chloride
(c) Sodium Bromide
(d) Sodium Acetate
During the electrolysis of an electrolyte, the number of ions produced, is directly
proportional to the
[AFMC 2002]
(a) Time consumed
(b) Electro chemical equivalent of electrolysis
(c) Quantity of electricity passed
(d) Mass of electrons
On electrolysing a solution of dilute H2SO4 between platinum electrodes, the gas
evolved at the anode is…
[MNR 1980; CBSE PMT 1992]
(a) SO2
(b) SO3
(c) O2
(d) H2
The products formed when an aqueous solution of NaBr is electrolysed in a cell
having inert electrodes are…
[AIIMS 2006]
(a) Na and Br2
(b) Na and O2
(c) H2, Br2 and NaOH
(d) H2 and O2
91.
92.
93.
94.
95.
96.
97.
98.
99.
100.
12
Electrolysis of aqueous HCl solution produces…
[CPMT 1987]
(a) H2 gas at the anode
(b) H2 gas at the cathode
(c) Cl2 gas at the cathode
(d) Cl2 and O2 gases both at the anode
During electrolysis of NaCl solution, part of the reaction is Na+ + e– → Na. This is
termed as
(a) Oxidation
(b) Reduction
(c) Deposition
(d) Cathode reaction
Brine solution (sea water) on electrolysis will not give…
[DCE 2006]
(a) NaOH
(b) Cl2
(c) H2
(d) O2
The passage of current liberates H2 at cathode and Cl2 at anode. The solution is…
[EAMCET 1987]
(a) Copper chloride in water
(b) NaCl in water
(c) H2SO4
(d) Water
Pure water does not conduct electricity because it…
[Manipal MEE 1995]
(a) Has a low boiling point
(b) Is almost totally unionized
(c) Is neutral
(d) Is readily decomposed
When 9.65 coulombs of electricity is passed through a solution of silver nitrate
(atomic weight of Ag = 107.87 taking as 108) the amount of silver deposited is…
[EAMCET 1992; KCET 2000]
(a) 10.8 mg
(b) 5.4 mg
(c) 16.2 mg
(d) 21.2 mg
Three faradays electricity was passed through an aqueous solution of iron (II)
bromide. The weight of iron metal (at. wt. = 56) deposited at the cathode (in gm) is…
[EAMCET 1991]
(a) 56
(b) 84
(c) 112
(d) 168
A silver cup is plated with silver by passing 965 coulombs of electricity, the
amount of silver deposited
[EAMCET 1990; MP PET 1994, 97]
(a) 9.89 g
(b) 107.87 g
(c) 1.0787 g
(d) 1.002 g
The atomic weight of Al is 27. When a current of 5 Faradays is passed through a
solution of Al+++ ions, the weight of Al deposited is
(a) 27 gm
(b) 36 gm
(c) 45 gm
(d) 39 gm
The unit of electrochemical equivalent is…
[EAMCET 1980]
(a) Gram
(b) Gram/ampere
(c) Gram/coulomb
(d) Coulomb/gram
101.
102.
103.
104.
105.
106.
107.
108.
109.
13
If the current is passed into solution of an electrolyte…
[AIIMS 1979]
(a) Anions move towards anode, cations towards cathode
(b) Anions and cations both move towards anode
(c) Anions move towards cathode, cations towards anode
(d) No movement of ions takes place
Unit of Faraday is
(a) Ampere
(b) Coulomb
(d) Coulomb sec–1
(c) Coulomb mole–1
On passing 0.1 Faraday of electricity through aluminium chloride, the amount of
aluminium metal deposited on cathode is (Al = 27)…
[MP PMT 1991]
(a) 0.9 gm
(b) 0.3 gm
(c) 0.27 gm
(d) 2.7 gm
5 amperes is passed through a solution of zinc sulphate for 40 minutes. Find the
amount of zinc deposited at the cathode…
[CBSE PMT 1996]
(a) 40.65 gm
(b) 4.065 gm
(c) 0.4065 gm
(d) 65.04 gm
In an electroplating experiment ‘m’ g of silver is deposited, when 4 amperes of
current flows for 2 minutes. The amount (in gms) of silver deposited by 6
amperes of current flowing for 40 seconds will be…
[MNR 1991]
(a) 4 m
(b) m /2
(c) m /4
(d) 2 m
On passing 3 amperes of electricity for 50 minutes, 1.8 gram metal deposits. The
equivalent mass of metal is…
[MP PMT 1992]
(a) 20.5
(b) 25.8
(c) 19.3
(d) 30.7
The desired amount of charge for obtaining one mole of Al from Al 3+
(a) 3 × 96500 C
(b) 96500 C
96500
96500
(c)
C
(d)
C
3
2
On passing one faraday of electricity through the electrolytic cells containing
Ag+, Ni+2 and Cr+3 ions solution, the deposited Ag (At. wt. = 108), Ni (At. wt. =
59) and Cr (At. wt. = 52) is
[AIIMS 1982]
Ag
Ni
Cr
(a) 108 gm
29.5 gm
17.3 gm
(b) 108 gm
59 gm
52.0 gm
(c) 108.0 gm 108.0 gm
108.0 gm
(d) 108 gm
117.5 gm
166.0 gm
One Faraday of electricity when passed through a solution of copper sulphate
deposits…
[CPMT 1978]
(a) 1 mole of Cu
(b) 1 gm atom of Cu
(c) 1 molecule of Cu
(d) 1 gm equivalent of Cu
110.
111.
112.
113.
114.
115.
116.
117.
118.
14
The platinum electrodes were immersed in a solution of cupric sulphate and
electric current passed through the solution. After some time it was found that
colour of copper sulphate disappeared with evolution of gas at the electrode.
The colourless solution contains…
(a) Platinum sulphate
(b) Copper hydroxide
(c) Copper sulphate
(d) Sulphuric acid
How many Faradays are required to generate one gram atom of magnesium
from MgCl2…
[MADT Bihar 1982]
(a) 1
(b) 2
(c) 3
(d) 4
To deposit 0.6354 gm of copper by electrolysis of aqueous cupric sulphate
solution, the amount of electricity required (in coulombs) is…
[MP PMT 1989]
(a) 9650
(b) 4825
(c) 3860
(d) 1930
The emf of the following Daniel cell at 298 K is E1.
Zn/ZnSO4(0.01M) || CuSO4(1.0 M) | Cu When concentration of ZnSO4 is 1.0 and that
of CuSO4 is 0.01 M, the emf is changed to E2. What is the relationship between E1
and E2 ?
(a) E1 > E2
(b) E1 < E2
(d) E1 = 0 ≠ E2
(c) E1 = E2
The reduction potential of hydrogen electrode will be positive if
(a) p(H2) = 1atm, [H+] = 1M
(b) p(H2) = 2atm, [H+] = 2M
(c) p(H2) = 2atm, [H+] = 1M
(d) p(H2) = 2.3atm, [H+] = 1.5M
Two platinum electrodes were immersed in a solution of CuSO4 and electric
current was passed through the solution. After some time it was found that the
colour of CuSO4 has disappeared with evolution of gas at the electrode. The
colorless solution contains
(a) platinum sulphate
(b) copper hydroxide
(c) sulphuric acid
(d) cuprous sulphate
+
Consider the cell at 25°C Tl | Tl (0.001M) || Cu2+(0.10M) | Cu for which emf is 0.84 V.
The emf of this cell could be increased by
(a) increasing [Tl+]
(b) increasing [Cu2+]
(c) decreasing [Cu2+]
(d) emf remains constant
The electrode potential of silver electrode dipped in a 0.1M solution of silver
nitrate at 25°C is (E°Ag | Ag+=0.80V) :
(a) 0.0741V
(b) 0.059V
(c) 0.741 V
(d) 0.859 V
Salt of A(at. mass=7), B(at. mass=27) and C(at. mass=64) were electrolyzed under
identical condition using same quantity of electricity. It was found that when 2.1
g of A was deposited, the weights of B and C deposited were 2.7 g and 9.6 g. The
valences of A, B and C are respectively:
(a) 3, 1 and 2
(b) 1, 3 and 2
(c) 3, 1 and 3
(d) 2, 3 and 2
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
15
The two platinum electrodes fitted in a conductance cell are 1.5 cm apart while
the cross sectional area of each electrode is 0.75 cm2. The cell constant is:
(a) 1.125
(b) 0.5
(c) 2.0
(d) 0.2
+
2+
For a cell reaction X + 2Y → X + 2Y Kc has been found to be 1012. The E°cell is:
(a) 0.708 V
(b) 1.36 V
(c) 0.354 V
(d) 1.006 V

+
For the cell reaction 4Br +O2 +4H → 2Br2 + 2H2O E°cell =0.16 V the value of
log Kc is :
(a) 108
(b) 10.8
(c) 5.4
(d) 1080
For an electrolytic solution of 0.05 mol L-1, the specific conductance has been
found to be 0.0110 S cm-1. The molar conductance is :
(a) 0.55 S cm2 mol-1
(b) 550 S cm2 mol-1
2
-1
(c) 0.22 S cm mol
(d) 220 S cm2 mol-1
The molar conductivities of AB and AC electrolytes are 120 and 160 ohm1cm2mol-1 respectively. If ionic molar conductance of C is 120 ohm-1 cm2 mol-1, the
ionic molar conductance of B is
(a) 400 ohm-1cm2mol-1
(b) 40 ohm-1cm2mol-1
(c) 80 ohm-1cm2mol-1
(d) 160 ohm-1cm2mol-1
How many coulombs of electricity are required for the oxidation of 1 mole of
H2O to O2?
(a) 96500 C
(b) 1.93 × 105 C
(c) 4.83× 105 C
(d) 9.65 × 106 C
The molar conductance of a 0.1 M solution of an electrolyte was found to be 400
ohm-1cm2mol-1. The cell constant of the cell is 0.1 cm-1. The resistance of the
solution is:
(a) 25 ohm
(b) 2000 ohm
(c) 200 ohm
(d) 400 ohm
The molar conductances of CH3COONa, HCl and NaCl at infinite dilution are 91,
426 and 126 S cm2 mol-1 respectively at 25°C. The molar conductance at infinite
dilution for CH3COOH would be
(a) 209 S cm2 mol-1
(b) 391 S cm2 mol-1
(c) 461 S cm2 mol-1
(d) none of these
What weight of copper will be deposited by passing 2 Faradays of electricity
through a cupric acid (At. mass = 63.5)?
(a) 63.5 g
(b) 31.75 g
(c) 127 g
(d) 2.0 g
The solution of copper sulphate in which copper rod is dipped is diluted to 10
times. The reduction potential of copper
(a) Decreases by about 60 mV
(b) Decreases by about 30 mV
(c) Decreases by about 30 V
(d) Increases by about 30 mV
If a salt bridge is removed between two half cells in an experiment, the voltage
(a) Does not change
(b) Increases rapidly
(c) Decreases slowly
(d) Falls to zero
130.
131.
132.
133.
134.
135.
136.
137.
138.
139.
16
When lead storage battery is charged, it acts as
(a) fuel cell
(b) an electrolytic cell
(c) a galvanic cell
(d) a concentration cell
Which of the following solutions will have highest equivalent conductance?
(a) 0.01 M NaCl
(b) 0.050 M NaCl
(c) 0.005 M NaCl
(d) 0.02 M NaCl
The standard electrode potential values of the element A, B and C are 0.68, -2.50
and -0.50 V respectively. The order of their reducing power is :
(a)A > B > C
(b) A > C >B
(c) C > B > A
(d) B > C > A
Two electrolytic cell, one containing acidified ferrous sulphate and other
containing acidified ferric sulphate are connected in series. The ratio of iron
deposited at cathodes in the two cell will be respectively
(a) 2 : 1
(b) 2 : 3
(c) 1 : 1
(d) 3 : 2
Which one of the following will increase the voltage of the cell?
Sn(s) + 2Ag+(aq) → Sn2+(aq) + 2Ag(s)
(a) Increase in the size of the silver rod
(b) Increase in the concentration of Sn2+ ion
(c) Increase in the concentration of Ag+ ions
The following four colourless salt solutions are placed in separate test tubes and
a strip of copper is placed in each. Which solution finally turns blue ?
The oxidation potentials of Zn, Ag, Cd and Pb are +0.76, -0.80, +0.40 and +0.13
respectively
(a) Zn(NO3)2
(b) AgNO3
(c) Cd(NO3)2
(d) Pb(NO3)2
A solution of sodium sulphate in water is electrolyzed using inert electrodes. The
products at the cathode and anode are respectively
(a) H2, SO2
(b) O2, H2
(c) O2, Na
(d) O2, SO2
As a lead storage battery is charged
(a) Lead dioxide dissolves
(b) Sulphuric acid is regenerated
(c) The lead electrode becomes coated with PbSO4
(d) The amount of H2SO4 decreases
On dilution of the molar conductance of an electrolyte
(a) Increases
(b) Decreases
(c) Remains unaffected
(d) May decrease or increase
An electric current is passed through silver voltmeter connected to a water
voltmeter weighed 0.108 g more at the end of electrolysis. The volume of oxygen
evolved at STP is
(a) 56 cm3
(b) 550 cm3
3
(c) 5.6 cm
(d) 11.2 cm3
140.
141.
142.
143.
144.
145.
146.
147.
148.
17
If three Faradays of electricity is passed through the solutions of AgNO3, CuSO4
and AuCl3, the molar ratio of the cations deposited at the cathodes will be
(a) 1 : 1 : 1
(b) 1 : 2 : 3
(c) 3 : 2 : 1
(d) 6 : 3 : 2
The specific conductance of a 0.1N KCl solution at 23°C is 0.012 ohm-1cm-1. The
resistance of the cell containing the solution at the same temperature was found
to be 55 ohm. The cell constant will be
(a) 0.142cm-1
(b) 0.616cm-1
(c) 0.918cm-1
(d) 1.12cm-1
In which cell, the free energy of a chemical reaction is directly converted into
electricity?
(a) Leclanche cell
(b) Concentration cell
(c) Fuel cell
(d) Lead storage battery
A gas X at 1 atm is bubbled through a solution containing a mixture of 1 M Y
and 1 M Z at 25°C. If the reduction potential of Z > Y > X, then
(a) Y will oxidize X and not Z
(b) Y will oxidize Z and not X
(c) Y will oxidize both X and Z
(d) Y will reduce both X and Z
Cu+(aq) is unstable in solution and undergoes simultaneous oxidation and
reduction according to the reaction, 2Cu+(aq) → Cu2+(aq) + Cu(s) . Choose correct E°
for the above reaction if E°Cu2+/Cu=0.34 V and E°Cu2+/Cu+=0.15 V
(a) +0.49 V
(b) + 0.38 V
(c) −0.19 V
(d) − 0.38 V
+
For the electrochemical cell, M | M || X | X, E°(M+/M)=0.44 V and E°(X/X )
=0.33 V. From this data, one can deduce that
(a) M + X → M+ + X is the spontaneous reaction
(b) M+ + X → M + X is the spontaneous reaction
(c) Ecell = 0.77 V
(d) Ecell = −0.77 V
The amount of an ion discharged during electrolysis is not dependent of :
(a) Resistance of solution
(b) Time
(c) Current strength
(d) Electrochemical equivalent of element
Which aqueous solution will conduct an electric current quite well ?
(a) Glycerol
(b) Sugar
(c) Hydrochloric acid
(d) Pure water
The unit of electrochemical equivalent is :
(a) gram
(b) gram/ampere
(c) gram/coulomb
(d) coulomb/gram
149.
150.
151.
152.
153.
154.
155.
156.
157.
158.
159.
18
Each of the three metals X, Y and Z were put in turn into aqueous solution of the
other two. Reduction potential of three metals are Z > Y > X. X + Salt of Y (or Z)
= Y (or Z) + Salt of X. Which observation is probably incorrect?
(a) Y + Salt of X = No action observed
(b) Y + Salt of Z = Z + Salt of Y
(c) Z + Salt of X = X + Salt of Z
(d) Z + Salt of Y = No action observed
Molten NaCl conducts electricity due to the presence of :
(a) Free electrons
(b) Free molecules
(c) Free ions
(d) Atoms of Na and Cl
Faraday’s law of electrolysis fails when :
(a) Temperature is increased
(b) Inert electrodes are used
(c) A mixture of electrolytes is used
(d) In none of the above cases
The electrolysis of a solution resulted in the formation of H2 at the cathode and
Cl2 at the anode. The liquid is :
(a) Pure water
(b) H2SO4 solution
(c) NaCl solution in water
(d) CuCl2 solution in water
In Dow’s method, sodium is prepared by the electrolysis of molten NaCl. The
reaction at cathode is :
(a) 2Cl– → Cl2(g) + 2e
(b) Na+ + e → Na(s)
(c) Na+ (aq) + e → Na+ + e
(d) Na+(aq) + e → Na(s)
The reaction, Cu2+ (aq) + 2Cl– (aq)→ Cu(s) + Cl2 (g) has E0cell = -1.03 V. This
reaction :
(a) Can be made to produce electricity in voltaic cell
(b) Can be made to occur in an electrolytic cell
(c) Can occur in acidic medium only
(d) Can occur in basic medium only
The best conductor of electricity is 1 M solution of :
(a) CH3COOH
(b) H2SO4
(c) H3PO4
(d) Boric acid
For which cell e.m.f. is independent of the concentrations of electrolytes used ?
(a) Fe | FeO(s) | KOH(aq) | NiO(s)|Ni2O3(s)| Ni
(b) Pt (H2) | HCl| Pt (Cl2)
(c) Zn|Zn(NO3)2 ||CuSO4|Cu
(d) Hg, HgCl2 | KCl || AgNO3 | Ag
Which metal can deposit copper from copper sulphate solution ?
(a) Mercury
(b) Iron
(c) Gold
(d) Platinum
If a salt bridge is removed from the two half cells, the voltage :
(a) Drops to zero
(b) Does not change
(c) Increases gradually
(d) Increases rapidly
In an aqueous solution, hydrogen (H2) will not reduce :
(a) Fe3+
(b) Cu2+
2+
(c) Zn
(d) Ag+
160.
161.
162.
163.
164.
165.
166.
167.
168.
169.
170.
171.
19
Which reaction occur at cathode during electrolysis of fused lead bromide?
(a) Pb → Pb2+ + 2e
(b) Br + e→ Br–
–
(c) Br → Br + e
(d) Pb2+ + 2e→ Pb
In a salt bridge, KCl is used because :
(a) It is an electrolyte
(b) It is good conductor of electricity
(c) The transport number of K+ and Cl– ions are nearly same or both have same
ionic mobility.
(d) It is ionic compound
Indicator electrode is :
(a) SHE
(b) Calomel electrode
(c) Ag/AgCl electrode
(d) Quinhydrone electrode
2+
3+
In the reaction, 2Al + 3Fe → 2Al + 3Fe possible ?
(a) No, because standard oxidation potential of Al < Fe
(b) Yes, because standard oxidation potential of Al > Fe
(c) Neither (a) nor (b)
(d) Data are unpredictable
The element that is easiest to be reduced is :
(a) Fe
(b) Cu
(c) Ag
(d) Sn
A dilute solution of Li2SO4 is electrolysed. The products formed at the anode and
cathode, respectively are :
(a) S and Li
(b) O2 and Li
(c) SO2 and O2
(d) O2 and H2
Which metal will dissolve, if the cell works Cu | Cu2+ || Ag+ |Ag ?
(a) Cu
(b) Ag
(c) Both (a) and (b)
(d) None of these
In the concentration cells, the electrical energy is produced due to :
(a) Oxidation of fuel
(b) Heat energy
(c) Chemical reaction
(d) Transfer of a substance from one concentration to other
The number of faraday required to liberate 1 mole of any element indicates :
(a) Weight of element
(b) Conductance of electrolyte
(c) Charge on the ion of that element
For a redox reaction to proceed spontaneously in a given direction, the e.m.f.
should :
(a) be zero
(b) have +ve sign
(c) have –ve sign
(d) have either +ve or –ve sign
KCl (aq) cannot be used as a salt bridge for the cell
Cu(s) |CuSO4 (aq) || AgNO3 (aq) |Ag (s) because :
(a) CuCl2 is precipitated
(b) Cl2 gas is given out
(c) AgCl is precipitated
(d) All of these
The electrode potential of a glass electrode depends upon :
(a) Concentration of chloride ions
(b) Concentration of hydrogen ions
(c) Concentration of KCl solution
172.
173.
174.
175.
176.
177.
178.
179.
180.
181.
182.
20
Which solution will show highest resistance during the passage of current?
(a) 1 N NaCl
(b) 0.1 N NaCl
(c) 2 N NaCl
(d) 0.05 N NaCl
Which represents disproportionation ?
(a) 2Cu+ →Cu2+ + Cu
(b) 3I2→ 5I– + I 5+
(c) H2O + Cl2 → Cl– + ClO– + 2H+
(d) All of the above
The oxidation potential of Mg and Al are +2.37 and +1.66 volt respectively. The
Mg in chemical reactions :
(a) Will be replaced by Al
(b) Will replace Al
(c) Will not be able to replace Al
The factor temperature coefficient for e.m.f. is :
(a) (δE /δT)P
(b) (δE /δP)T
(d) None of these
(c) (δE /δV)T
3 faraday of electricity is passed through molten Al2O3, aqueous solution of
CuSO4 and molten NaCl taken in three different electrolytic cell. The amount of
aluminium, copper and sodium deposited at the cathode will be in the ratio of :
(a) 1 mole : 2 mole : 3 mole
(b) 1.5 mole : 2 mole : 3 mole
(c) 1 mole : 1.5 mole : 3 mole
(d) 1 mole : 3 mole : 2 mole
The reduction potentials of four metals P, Q, R and S are – 2.90, + 0.34,
+ 1.20 and – 0.76 respectively. Reactivity decreases in the order :
(a) P > Q > R > S
(b) Q > P > R > S
(c) R > Q > S > P
(d) P > S > Q > R
Which metal does not give the following reaction ?
M + water or steam → oxide + H2 ↑
(a) Iron
(b) Sodium
(c) Mercury
(d) Magnesium
A galvanic cell is composed of two hydrogen electrodes, one of which is a
standard one. In which of the following solutions should the other electrode be
immersed to get maximum e.m.f. ?
(a) 0.1 M HCl
(b) 0.1 M CH3COOH
(c) 0.1 M H3 PO4
(d) 0.1 M H2SO4
The thermodynamic efficiency of cell is given by :
(a) ∆H / ∆G
(b) nFE /∆G
(c) nFE / ∆H
(d) nFE0
E0 of an electrode is :
(a) Extensive property
(b) Constitutive property
(c) Colligative property
(d) Additive property
2+
Standard electrode potentials of Fe + 2e → Fe and Fe+ + 3e → Fe are – 440
V and – 0.036 V respectively. The standard electrode potential (E0) for Fe3+ + e
→ Fe2+ is :
(a) – 0.476 V
(b) – 0.404 V
(c) + 0.404 V
(d) +0.772 V
183.
184.
185.
186.
187.
188.
189.
190.
191.
21
1 mole of Al is deposited by X coulomb of electricity passing through aluminium
nitrate solution. The number of mole of silver deposited by X coulomb of
electricity from silver nitrate solution is :
(a) 3
(b) 4
(c) 2
(d) 1
Copper from copper sulphate solution can be displaced by … The standard
reduction potentials of some electrodes are given below.
E0 (Fe2+ , Fe) = – 0.44 V ; E0 (Zn2+ , Zn) = – 0.76 V ;
E0 (Cu2+ , Cu) = + 0.34 V ; E0 (Cr3+ , Cr) = – 0.74 V ;
1


E0  H 3 O + , H 2  = –0.00V


2
(a) H2
(b) Zn
(c) Cr
(d) Fe
(e) All
The number of faraday required to generate 1 g-atom of Mg from MgCl2 is
(a) 1
(b) 2
(c) 3
(d) 4
2
3
E.M.F. of cell Ni || Ni + (1.0 M) || Au + (1.0 M) | Au is ….. If E0 for Ni2+ | Ni
is – 0.25 V, E0 for Au3+ | Au is 1.50 V.
(a) + 1.25 V
(b) – 1.75 V
(c) + 1.75 V
(d) + 4.0 V
0
E for the half cell reactions are as, Zn = Zn2+ + 2e; E0 = + 0.76 V; Fe = Fe2+ + 2e; E0
=+ 0.41 V. The E0 for the cell reaction, Fe2+ + Zn → Zn2+ + Fe is :
(a) – 0.35 V
(b) + 0.35 V
(c) + 1.17 V
(d) – 0.17 V
A certain current liberates 0.504 g of hydrogen in 2 hr. How many gram of
copper can be liberated by the same current flowing for the same time in CuSO4
solution ?
(a) 12.7
(b) 16
(c) 31.8
(d) 63.5
Passage of three faraday of charge through aqueous solution of AgNO3, CuSO4,
Al(NO3)3 and NaCl will deposit metals at the cathode in the molar ratio of :
(a) 1 : 2 : 3 : 1
(b) 6 : 3 : 2 : 6
(c) 6 : 3 : 0 : 0
(d) 3 : 2 : 1 : 0
0
The standard potentials at 25 C for the following half reactions are given below,
Zn2+ + 2e →Zn ; E0 = – 0.762 V ; Mg2+ + 2e → Mg : E0 = – 2.37 V
When zinc dust is added to the solution of MgCl2 :
(a) ZnCl2 is formed
(b) Zinc dissolves in the solution
(c) No reaction takes place
(d) Mg is precipitated
Normal Al–AlCl3 coupled with normal hydrogen electrode gives an e.m.f. of
1.66 V. The standard oxidation electrode potential of aluminium is :
(a) – 1.66 V
(b) + 1.66 V
(c) – 0.83 V
(d) + 0.83 V
192.
193.
194.
195.
196.
197.
198.
199.
200.
201.
22
The cell reaction for the given cell is spontaneous if :
PtCl2 |Cl– (1M) || Cl– (1 M)| PtCl2
P1
P2
(a) P1 > P2
(b) P1 < P2
(c) P1 = P2
(d) P2 = 1 atm
On passing electricity through dilute H2SO4 solution the amount of substance
liberated at the cathode and anode are in the ratio :
(a) 1 : 8
(b) 8 : 1
(c) 16 : 1
(d) 1 : 16
During electrolysis of an aqueous solution of Cu2+ sulphate, 0.635 g of copper
was deposited at cathode. The amount of electricity consumed in coulomb is :
(a) 1930
(b) 3860
(c) 9650
(d) 4825
If Mg2+ + 2e → Mg(s) ; E = – 2.37 V, Cu2+ + 2e → Cu(s) ; E = +0.34 V ? The
e.m.f. of the cell Mg | Mg2+ || Cu2+ | Cu is :
(a) 2.71 V
(b) 2.30 V
(c) 2.80 V
(d) 1.46 V
A certain quantity of electricity is passed through aqueous solution of AgNO3
and CuSO4 connected in series. If Ag (at. wt. 108) deposited at the cathode is 1.08
g then Cu deposited at the cathode is (at. wt. of Cu is 63.53) :
(a) 6.354 g
(b) 0.317 g
(c) 0.6354 g
(d) 3.177 g
The number of electrons passing per second through a cross-section of Cu wire
carrying 10 ampere is :
(a) 6 × 1019
(b) 8 × 1019
19
(d) 1.6 × 1019
(c) 1 × 10
The same amount of electricity was passed through two cells containing molten
Al2O3 and molten NaCl. If 1.8 g of Al were liberated in one cell, the amount of Na
liberated in the other cell is :
(a) 4.6 g
(b) 2.3 g
(c) 6.4 g
(d) 3.2 g
In the electrolysis of CuCl2 solution using Cu electrodes the mass of cathode
increases by 3.18 g. What happened at the other electrode ?
(a) 0.05 mole of Cu2+ ions passed into solution
(b) 0.112 litre of Cl2 was liberated
(c) 0.56 litre O2 was liberated
(d) 0.56 litre O2 was liberated
(d) 0.1 mole of Cu2+ ions passed into the solution
Number of faraday required to liberate 8 g of H2 is :
(a) 8
(b) 16
(c) 4
(d) 2
The weight ratio of Al and Ag deposited using the same quantity of current is :
(a) 9 : 108
(b) 2 : 12
(c) 108 : 9
(d) 3 : 8
202.
203.
204.
205.
206.
207.
208.
209.
210.
211.
212.
23
20 g of chlorine are evolved in 6 hour from sodium chloride solution by the
current of :
(a) 5 ampere
(b) 10 ampere
(c) 2.5 ampere
(d) 50 ampere
What weight of copper will be deposited by passing 2 faraday of electricity
through a solution of Cu (II) salt ?
(a) 35.6 g
(b) 63.5 g
(c) 6.35 g
(d) 3.56 g
Passage of 1 faraday of electricity through a solution of CuSO4, deposits :
(a) 1 mole of Cu
(b) 1 g atom of Cu
(c) 1 molecule of Cu
(d) 1 g equivalent of Cu
The amounts of sodium deposited by 5 ampere current for 10 minute from fused
NaCl is :
(a) 0. 715 g
(b) 71.5 g
(c) 5.17 g
(d) 0.517 g
–2
10 g atom of Ag can be oxidised to Ag+ during the electrolysis of AgNO3
solution using silver electrode by :
(a) 965 coulomb
(b) 96500 coulomb
(c) 9650 coulomb
(d) 96.500 coulomb
How many coulomb of electricity are consumed when 100 mA current is passed
through a solution of AgNO3 for 30 minute during an electrolysis experiment ?
(a) 108
(b) 18000
(c) 180
(d) 3000
Total charge on 1 mole of a monovalent metal ion is equal to :
(a) 6.28 × 1018 coulomb
(b) 1.6 × 10–19 coulomb
(c) 9.65 × 104 coulomb
(d) None of these
The amount of energy expanded during the passage of one ampere current for
100 second under a potential of 115 V is :
(a) 20 kJ
(b) 11.5 kJ
(c) 115 kJ
(d) 0.115 kJ
Deduce from the following E0 values of half cells, what combination of two half
cells would result in a cell with the largest potential ?
(i) A + e → A– ; E0 = – 0.24 V
(ii) B– + e → B2– ; E0 = + 1.25 V
(iii) C– + 2e → C3– ; E0 = - 1.25 V
(iv) D + 2e → D2– ; E0 = + 0.68 V
(a) (ii) and (iii)
(b) (ii) and (iv)
(c) (i) and (iii)
(d) (i) and (iv)
0
0
E for F2 + 2e = 2F is 2.8 V, E for ½ F2 + e = F– is :
(a) 2.8 V
(b) 1.4 V
(c) – 2.8 V
(d) – 1.4 V
+
2+
For the cell, Tl | Tl (0.001M) || Cu (0.1 M) |Cu, Ecell at 250C is 0.83 V. Ecell can
be increased :
(a) By increasing [Cu2+]
(b) By increasing [Tl+]
2+
(c) By decreasing [Cu ]
(d) None of these
213.
214.
215.
216.
217.
218.
219.
220.
221.
24
The charge required for the reduction of 1 mole of Cr2O72– ions to Cr3+ is :
(a) 96500 C
(b) 2 × 96500 C
(c) 3 × 96500 C
(d) 6 × 96500 C
10800 C of electricity on passing through the electrolyte solution deposited 2.977
of metal with atomic mass 106.4 g mol–1 the charge on the metal cation is :
(a) + 4
(b) + 3
(c) +2
(d) +1
1 coulomb of charge passes through solution of AgNO3 and CuSO4 connected in
series and the concentration of two solution being in the ratio 1 : 2. The ratio of
amount of Ag and Cu deposited on Pt electrode is :
(a) 107.9 : 63.54
(b) 54 : 31.77
(c) 107.9 : 31.77
(d) 54 : 63.54
During electrolysis of H2O, the molar ratio of H2 and O2 formed is :
(a) 2 : 1
(b) 1 : 2
(c) 1 : 3
(d) 1 : 1
A hydrogen electrode placed in a buffer solution of CH3COONa and acetic acid
in the ratio’s x : y and y : x has electrode potential values E1 volt and E2 volt
respectively at 250C. The pKa values of acetic acid is (E1 and E2 are oxidation
potential) :
E + E2
E − E1
(a) 1
(b) 2
0.118
0.118
E1 + E2
E1 − E2
(c) −
(d)
0.118
0.118
The weight of silver (eq. wt. = 108) displaced by that quantity of current which
displaced 5600 mL of hydrogen at STP is :
(a) 54 g
(b) 108 g
(c) 5.4 g
(d) None of these
The time required to coat a metal surface of 80 cm2 with 5 × 10–3 cm thick layer
of silver (density 1.05 g cm–3) with the passage of 3A current through a silver
nitrate solution is :
(a) 115 sec
(b) 125 sec
(c) 135 sec
(d) 145 sec
Salts of A (atomic weight 7), B (atomic weight 27) and C (atomic weight 48) were
electrolysed under identical conditions using the same quantity of electricity. It
was found that when 2.1 g of A was deposited, the weights of B and C deposited
were 2.7 g and 7.2 g. The valencies of A, B and C are respectively :
(a) 3, 1 and 2
(b) 1, 3 and 2
(c) 3, 1 and 3
(d) 2, 3 and 2
To produce 160 g of oxygen, the number of mole of water required to be
electrolysed is :
(a) 2.5
(b) 5
(c) 10
(d) 20
222.
223.
224.
225.
226.
227.
228.
229.
25
A current is passed through two voltameters connected in series. The first
voltameter contains XSO4 (aq) while the second voltameter contains Y2SO4 (aq).
The relative atomic masses of X and Y are in the ratio of 2 : 1. The ratio of the
mass of X liberated to the mass of Y liberated is :
(a) 1 : 1
(b) 1 : 2
(c) 2 : 1
(d) none of these
The standard oxidation potentials of the electrodes Ag | Ag+, Sn |Sn2+, Ca |Ca2+,
Pb | Pb2+ are – 0.8, 0.136, 2.866 and 0.126 V respectively. The most powerful
oxidising agent among these metal ions is :
(a) Pb2+
(b) Ca2+
(c) Sn2+
(d) Ag+
Silver is removed electrolytically from 200 mL of a 0.1 N solution of AgNO3 by a
current of 0.1 ampere. How long will it take to remove half of the silver from the
solution ?
(a) 10 sec
(b) 16 sec
(c) 100 sec
(d) 9650 sec
The atomic weight of Al is 27. When a current of 5 faraday is passed through a
solution of Al3+ ions, the wt. of Al deposited is :
(a) 27 g
(b) 36 g
(c) 45 g
(d) 9 g
Maximum number of mole of oxygen gas that can be obtained by the electrolytic
decomposition of 90 g of water will be :
(a) 1
(b) 2.5
(c) 5
(d) 9
0
+
–
For the reactions at 25 C, Ag (aq) + e = Ag(s); E0 = + 0.80 V
Sn2+(aq) + 2e– = Sn(s) ; E0 = – 0.14 V
What is the e.m.f. of the cell represented as Sn | Sn2+ || Ag+ | Ag ? If each ion
having unit concentration:
(a) 0.66 V
(b) 0.80 V
(c) 0.94 V
(d) 1.08 V
What is the potential of the cell containing two hydrogen electrodes as
represented below,
Pt ; ½ H2(g) | H+ (10–8 M) || H+ (0.001 M) | 1/2H2 (g) Pt ?
(a) – 0.295 V
(b) – 0.0591 V
(c) 0.295 V
(d) 0.0591 V
Chromium plating can involve the electrolysis of an electrolyte of an acidified
mixture of chromic acid and chromium sulphate. If during electrolysis the article
being plated increases in mass by 2.6 g and 0.6 dm3 of oxygen are evolved at an
inert anode, the oxidation state of chromium ions being discharged must be :
(assuming Cr= 52 and 1 mole of gas at room temperature and pressure occupies
a volume of 24 dm3)
(a) –1
(b) zero
(c) +1
(d) +2
230.
231.
232.
A current of i ampere was passed for t second through three cells P, Q and R
connected in series. These contain respectively silver nitrate, mercuric nitrate and
Mercurous nitrate. At the cathode of the cell P, 0.216 g of Ag was deposited. The
weights of mercury deposited in the cathode of Q and R respectively are :
(a) 0.4012 and 0.8024 g
(b) 0.4012 and 0.2006 g
(c) 0.2006 and 0.4012 g
(d) 0.1003 and 0.2006 g
Two electrolytic cells, one containing acidified ferrous chloride and another
acidified ferric chloride are connected in series. The ratio of iron deposited at
cathodes in the two cells when electricity is passed through the cells will be :
(a) 3 : 1
(b) 2 : 1
(c) 1 : 1
(d) 3 : 2
0
0
Given that E Fe3 +|Fe and E Fe2 +|Fe are – 0.36 V and – 0.439 V, respectively. The
value of E0 Fe3 + ,Fe2 +|Pt would be :
233.
234.
235.
236.
237.
26
(a) (–36 – 0.439) V
(b) [3(–0.36) +2 (–0.439)]V
(c) ( – 0.36 + 0.439) V
(d) [3 (– 0.36) –2 (– 0.439)] V
The same amount of electricity was passed through two separate electrolytic cells
containing solutions of nickel nitrate and chromium nitrate respectively. If 0.3 g
of nickel was deposited in the first cell, the amount of chromium deposited is :
(at. wt. Ni = 59, Cr = 52)
(a) 0.1 g
(b) 0.17 g
(c) 0.3 g
(d) 0.6 g
Given electrode potentials are ,
Fe3+ + e → Fe2+ ; E0 = 0.771 V
I2 + 2e → 2I– ;
E0 = 0.536 V
E0 cell for the cell reaction, 2Fe3+ + 2I– → 2Fe2+ + I2 is :
(a) (2 × 0.771 – 0.536) = 1.006 V
(b) (0.771 – 0.5 × 0.536) = 0.503 V
(c) 0.771 – 0.536 = 0.235 V
(d) 0.536 – 0.771 = – 0.235 V
During electrolysis of fused sodium chloride, the reaction of the electrodes are :
Anode
Cathode
+
(a) Na + e → Na
Cl– → ½ Cl +e
(b) Na→ Na+ + e
½ Cl2 + e → Cl–
(c) Cl– → ½ Cl2 + e
Na+ + e → Na
(d) ½ Cl2 + e → Cl–
Na → Na+ + e
The e. m. f. of the cell Zn | Zn2+ (1 M) || Cu2+ | Cu (1 M) is 1.1 volt. If the
standard reduction potential of Zn2+ | Zn is – 0.78 volt, what is the oxidation
potential of Cu|Cu2+ ?
(a) + 1.86 V
(b) 0. 32 V
(c) – 0.32 V
(d) – 1.86 V
For I2 + 2e → 2I–, standard reduction potential = + 0.54 volt. For 2Br+ → Br2 + 2e–,
standard oxidation potential = – 1.09 volt. For Fe → Fe2+ + 2e–, standard
oxidation potential = + 0.44 volt. Which of the following reactions is nonspontaneous ?
(a) Br2 + 2I– → 2 Br– + I2
(b) Fe + Br2 → Fe2+ + 2Br–
(c) Fe + I2 → Fe2+ + 2I–
(d) I2 + 2Br– → 2I– + Br2
238.
239.
240.
241.
242.
243.
244.
245.
246.
27
The hydrogen electrode is dipped in a solution of pH = 3 at 250C. The potential of
the cell would be (the value of 2.303RT/F is 0.059 V)
[KCET 1993, 2005]
(a) 0.177 V
(b) – 0.177 V
(c) 0.087 V
(d) 0.059 V
The reaction Zn2+ + 2e– →Zn has a standard potential of – 0.76 V. This means
[KCET 1992]
(a) Zn can’t replace hydrogen from acids
(b) Zn is a reducing agent
(c) Zn is an oxidising agent
(d) Zn2+ is a reducing agent
2H+(aq) + 2e– →H2(g). The standard electrode potential for the above reaction is
(in volts)
[CPMT 1988]
(a) 0
(b) +1
(c) –1
(d) None of these
K, Ca and Li metals may be arranged in the decreasing order of their standard
[CPMT 1990]
electrode potentials as
(a) K, Ca, Li
(b) Ca, K, Li
(c) Li, Ca, K
(d) Ca, Li, K
The correct order of chemical reactivity with water according to electrochemical
series
[MP PMT 1991]
(a) K > Mg > Zn > Cu
(b) Mg > Zn > Cu > K
(c) K > Zn > Mg > Cu
(d) Cu > Zn > Mg > K
Oxidation and reduction take place in a cell, then its electromotive force will be
[RPET 1999]
(a) Positive
(b) Negative
(c) Zero
(d) Stable
The standard electrode potential for the two electrode A+/A and B+/B are
respectively 0.5 V and 0.75 V. The emf of the given cell
A|A+ (a = 1) || B+ (a = 1) | B will be
(a) 1.25 V
(b) – 1.25 V
(c) – 0.25V
(d) 0.25 V
2+
Electrode potential of Zn /Zn is – 0.76 V and that of Cu2+/Cu is +0.34 V. The
EMF of the cell constructed between these two electrodes is
[KCET 1990; EAMCET 1992; MH CET 1999, 2003; AFMC 2001; CBSE PMT
2001; BHU 2001; Pb. CET 2002; Pb. PMT 2004; CPMT 2006]
(a) 1.10 V
(b) 0.42 V
(c) –1.1V
(d) – 0.42V
EMF of a cell whose half cells are given below is
Mg2+ + 2e–→Mg(s); E = – 2.37 V
Cu2+ + 2e– → Cu(s); E = +0.33 V
[EAMCET 1987; MP PET 1994; Pb. PMT 2000]
(a) – 2.03 V
(b) 1.36 V
(c) 2.7 V
(d) 2.03 V
247.
248.
249.
250.
251.
252.
253.
254.
28
A cell constructed by coupling a standard copper electrode and a standard
magnesium electrode has EMF of 2.7 volts. If the standard reduction potential of
copper electrode is +0.34 volt that of magnesium electrode is [KCET 1989]
(a) + 3.04 volts
(b) –3.04 volts
(c) + 2.36 volts
(d) – 2.36 volts
Which substance eliminates bromine from KBr solution
[IIT 1981; BVP 2003]
(a) I2
(b) Cl2
(c) HI
(d) SO2
In the electrochemical cell
H2(g) 1 atm |H+(1M) || Cu2+ (1M) | Cu(s)
Which one of the following statements is true
[EAMCET 1997]
(a) H2 is cathode; Cu is anode
(b) Oxidation occurs at Cu electrode
(c) Reduction occurs at H2 electrode
(d) H2 is anode; Cu is cathode
Amongst the following electrodes the one with zero electrode potential is
[MP PMT 1997; Orissa JEE 2008]
(a) Calomel electrode
(b) Standard hydrogen electrode
(c) Glass electrode
(d) Gas electrode
Which of the following is correct expression for electrode potential of a cell
[MP PMT 1997]
RT [ product ]
RT [ product ]
(a) E = E0 −
ln
(b) E = E0 +
ln
nF [ reactant ]
F
[reactant ]
RT [ product ]
RT [ reactant ]
(c) E = E0 −
ln
(d) E = −
ln
nF [ product ]
F
[reactant ]
E0 for the cell Zn|Zn2+(aq)||Cu2+(aq)|Cu is 1.10V at 250C, the equilibrium
constant for the reaction Zn + Cu2+(aq) Cu + Zn2+ (aq) is of the order of
[CBSE PMT 1997]
–28
(a) 10
(b) 10–37
(c) 10+18
(d) 10+17
The e.m.f. of the cell in which the following reaction Zn (s) + Ni2+ (a=1.0) Zn2+
(a=10) + Ni(s) occurs, is found to be 0.5105 V at 298K. The standard e.m.f. of the
cell is
[Roorkee Qualifying 1998]
(a) 0.5400
(b) 0.4810 V
(c) 0.5696 V
(d) – 0.5105 V
The E0 for half cells Fe /Fe2+ and Cu/Cu2+ are – 0.44 V and +0.32 V respectively.
Then
[MP PMT 2003]
2+
(a) Cu oxidises Fe
(b) Cu2+ oxidises Fe2+
(c) Cu oxidises Fe2+
(d) Cu reduces Fe2+
255.
256.
257.
258.
259.
260.
The potential of the cell for the reaction
M(s) + 2H+(1M) → H2(g), (1 atm) + M2+ (0.1 M) is 1.500 V. The standard reduction
potential for M2+/M(s) couple is
[AMU (Engg.) 2009]
(a) 0.1470 V
(b) 1.470 V
(c) 14.70 V
(d) None of these
Given :
(i) Cu2+ + 2e– → Cu, E0 = 0.337 V
(ii) Cu2+ + 2e– → Cu+, E0 = 0.153 V
Electrode potential E0 for the reaction, Cu+ + e– → Cu will be
[CBSE PMT 2009; AMU PMT 2009]
(a) 0.52 V
(b) 0.90 V
(c) 0.30 V
(d) 0.38 V
For a cell reaction involving a two-electron change, the standard emf of the cell is
found to be 0.295 V at 250C. The equilibrium constant of the reaction at 250C will
be
[Roorkee 1999; AIEEE 2003; CBSE PMT 2004]
–10
(b) 29.5 × 10–2
(a) 1 × 10
(c) 10
(d) 1 ×1010
Reduction potentials of A, B, C and D are 0.8 V, 0.79V, 0.34V and –2.37V
respectively. Which element displaces all the other three elements
[MP PET 2006]
(a) B
(b) A
(c) D
(d) C
What is the potential of a cell containing two hydrogen electrodes the negative
one in contact with 10–8 M H+ and positive one in contact with 0.025 M H+
[MP PMT 2000]
(a) 0.18 V
(b) 0.28 V
(c) 0.38 V
(d) 0.48 V
+
Cu ion is not stable in aqueous solution because of disproportionation reaction.
E0 value for disproportionation of Cu+ is
0
0
= 0.15, ECu
= 0.34V ) [IIT 1995]
(Given ECu
2+
2+
/Cu+
/Cu
262.
(a) – 0.49 V
(b) 0. 49 V
(c) – 0. 38V
(d) 0.38 V
What is the potential of a half-cell consisting of zinc electrode in 0.01m ZnSO4
solution at 2580 C (E0 = 0.763V)
[AIIMS 2000; BHU 2000]
(a) 0.8221 V
(b) 8.221 V
(c) 0.5282 V
(d) 9.232 V
0
0
If EFe2+ /Fe = −0.441V and EFe3+ /Fe2+ = 0.771V , the standard EMF of the reaction
263.
Fe + 2 Fe 3+ → 3Fe 2 + will be
[CBSE PMT 2006]
(a) 1.212 V
(b) 0.111 V
(c) 0.330 V
(d) 1.653 V
0
4+
3+
For the cell reaction, 2Ce + Co → 2Ce + Co2+ E0Cell is 1.89V and ECo
= −0.028.
/Co2 +
261.
29
0
If ECe
4+
/Ce 3+
[Pb. CET 2000]
(a) – 1.64 V
(c) – 2.08 V
(b) + 1.64 V
(d) + 2.17 V
264.
Cr2O72 − + I − → I 2 + Cr 3+
0
Ecell
= 0.79V ; Ecr0 O2− = 1.33V , EI02 is
2
265.
266.
[BVP 2004]
7
(a) – 0. 10 V
(b) + 0.18 V
(c) – 0. 54 V
(d) + 0.54 V
The rusting of iron takes place as follows
2H++ 2e– + 1/2O2 → H2O(l) ; E0 = + 1.23V
Fe2++ 2e–→ Fe(s); E0 = – 0.44 V
Calculate ∆G0 for the net process
[IIT 2005]
–1
(a) – 322 kJ mol
(b) – 161 kJ mol–1
(c) – 152 kJ mol–1
(d) – 76 kJ mol–1
Ecell = 0.78 volt for the following cell.
Fe(s) |Fe 2 +( aq ) ||Cu 2 + ( aq ) |Cu( s )
(xM )
0
Fe /Fe 2 +( aq )
E
267.
268.
269.
270.
271.
30
(0.01 M )
0
= 0.44 V , ECu
/Cu2 +
( aq )
= −0.34V
[Gujarat CET 2007]
(a) x cannot be predicted
(b) x = 0.01 M
(c) x > 0.01 M
(d) x < 0.01 M
On the basis of the following E0 values, the strongest oxidizing agent is
[Fe(CN)6]4- → [Fe(CN) 6]3– + e–1; E0 = – 0.35V
Fe2+ → Fe3+ e– ;
E0 = – 0.77V
[CBSE PMT 2008]
(a) Fe3+
(b) [Fe(CN)6]3–
(c) [Fe(CN)6]4
(d) Fe2+
On passing C ampere of electricity through a electrolyte solution for t second, m
gram metal deposits on cathode. The equivalent weight E of the metal is [MP
PMT 1990]
C ×t
C ×m
(a) E =
(b) E =
m × 96500
t × 96500
96500 × m
C × t × 96500
(c) E =
(d) E =
C ×t
m
When 0.04 faraday of electricity is passed through a solution of CaSO4, then the
weight of Ca2+ metal deposited at the cathode is
[BHU 1996]
(a) 0.2 gm
(b) 0.4 gm
(c) 0.6 gm
(d) 0.8 gm
How many atoms of calcium will be deposited from a solution of CaCl2 by a
current of 25 milliamperes flowing for 60 seconds
[BHU 1999]
18
(a) 4.68 × 10
(b) 4.68 × 1015
(c) 4.68 × 1012
(d) 4.68 × 109
On passing 0.5 faraday of electricity through NaCl, the amount of Cl deposited
on cathode is
[BHU 1997; RPET 1999]
(a) 35.5 gm
(b) 17.75 gm
(c) 71 gm
(d) 142 gm
272.
273.
274.
275.
276.
277.
278.
279.
280.
31
What is the amount of chlorine evolved when 2 amperes of current is passed for
30 minutes in an aqueous solution of NaCl
[BHU 1998; AIIMS 1999]
(a) 66 g
(b) 1.32 g
(c) 33 g
(d) 99 g
On passing a current through KCl solution, 19.5 g of potassium is deposited. If
the same quantity of electricity is passed through a solution of aluminium
chloride, the amount of aluminium deposited is
[EAMCET 1997]
(a) 4.5 g
(b) 9.0 g
(c) 13.5 g
(d) 27 g
(e) None is correct
A current being passed for two hour through a solution of an acid liberating 11.2
litre of oxygen at NTP at anode. What will be the amount of copper deposited at
the cathode by the same current when passed through a solution of copper
[BVP 2003]
sulphate for the same time
(a) 16 g
(b) 63 g
(c) 31.5 g
(d) 8 g
In a metal oxide, there is 20% oxygen by weight. Its equivalent weight is
[Pb. PMT 2000]
(a) 40
(b) 64
(c) 72
(d) 32
How much chlorine will be liberated on passing one ampere current for 30
minutes through NaCl solution
[BVP 2003; BHU 2005]
(a) 0.66 mole
(b) 0.33 mole
(c) 0.66 gm
(d) 0.33 gm
Calculate the volume of H2 gas at NTP obtained by passing 4 amperes through
acidified H2O for 30 minutes is
[DCE 2005]
(a) 0.0836 L
(b) 0.0432 L
(c) 0.1672 L
(d) 0.836 L
The number of electrons passing per second through a cross-section of copper
wire carrying 10–6 amperes of current per second is found to be
[EAMCET 1985]
(a) 1.6 × 10–19
(b) 6 × 10–35
(c) 6 × 10–16
(d) 6 × 1012
When 96500 coulomb of electricity is passed through a copper sulphate solution,
the amount of copper deposited will be [MP PMT 1996; Similar MP PMT 1995]
(a) 0.25 mol
(b) 0.50 mol
(c) 1.00 mol
(d) 2.00 mol
During electrolysis of fused aluminium chloride 0.9 gm of aluminium was
deposited on the cathode. The volume of chlorine liberated at the anode will be
(a) 2.24 litres
(b) 11.2 litres
(c) 1.12 litres
(d) 5.6 litres
281.
282.
283.
284.
285.
286.
287.
288.
289.
32
The required charge for one equivalent weight of silver deposited on cathode is
[Roorkee 1995]
7
(a) 9.65 × 10 C
(b) 9.65 × 104 C
(c) 9.65 × 103 C
(d) 9.65 × 105 C
Al2O3 is reduced by electrolysis at low potential and high currents. If 4.0 × 104
amperes of current is passed through molten Al2O3 for 6 hours, what mass of
aluminium is produced (Assume 100% current efficiency, At.mass of Al =27 g
mol–1)
[CBSE PMT 2009]
(a) 9.0 × 103 g
(b) 8.1 × 104 g
(c) 2.4 × 105 g
(d) 1.3 × 104 g
A current of strength 2.5 amp was passed through CuSO4 solution for 6 minutes
26 seconds. The amount of copper deposited is(Atomic weight of Cu = 63.5)(1
faraday = 96500 coulombs)
[EAMCET 1989; MP PET 1994]
(a) 0.3175 g
(b) 3.175 g
(c) 0.635 g
(d) 6.35 g
A certain quantity of electricity is passed through an aqueous solution of AgNO3 and
cupric salt solution connected in series. The amount of Ag deposited is 1.08 gm, the
amount of copper deposited is (atomic weight of Cu = 63.5; Ag = 108)
[EAMCET 1986]
(a) 0.6454 g
(b) 6.354 g
(c) 0.3177 g
(d) 3.177 g
The number of electrons required to deposit 1 gm atom of aluminium
(at. wt. = 27) from a solution of aluminium chloride will be (where N is
Avogadro’s number)
[AIIMS 1992]
(a) 1 N
(b) 2 N
(c) 3 N
(d) 4 N
The number of coulombs required to reduce 12.3 g of nitrobenzene to aniline
[UPSEAT 2003]
(a) 115800 C
(b) 5790 C
(c) 28950 C
(d) 57900 C
An electrolytic cell contains a solution of Ag2SO4 and has platinum electrodes. A
current is passed until 1.6 gm of O2 has been liberated at anode. The amount of
silver deposited at cathode would be
[CPMT 1971]
(a) 107.88 gm
(b) 1.6 gm
(c) 0.8 gm
(d) 21.60 gm
The amount of copper deposited by one Faraday current will be maximum in an
acidic solution of one litre of
[Kerala PMT 2006]
(a) 1M Cu2Cl2
(b) 2M Cu (NO3)2
(c) 5M CuSO4
(d) 5M Cu3 (PO4)2
(e) 10M CuF2
The number of Faradays needed to reduce 4 gram equivalents of Cu++ to Cu
metal will be
[BHU 1981]
(a) 1
(b) 2
(c) 1/2
(d) 4
290.
291.
292.
293.
294.
295.
296.
297.
33
On electrolysis, 1 mole of aluminium will be deposited from its molten salt by
[MH CET 2000]
(a) 3 moles of electron
(b) 4 moles of electrons
(c) 2 moles of electrons
(d) 1 mole of electrons
The atomic weight of Fe is 56. The weight of Fe deposited from FeCl3 solution by
passing 0.6 Faraday of electricity is
[MH CET 2000]
(a) 5.6 g
(b) 11.2 g
(c) 22.4 g
(d) 33.6 g
If the aqueous solutions of the following salts are electrolysed for 1 hour with 10
ampere current, which solution will deposit the maximum mass of the metal at
the cathode. The atomic weights are, Fe = 56, Zn = 65, Ag = 108, Hf = 178 and W
= 184
[Kerala PMT 2006]
(a) ZnSO4
(b) FeCl3
(c) HfCl4
(d) WCl6
(e) AgNO3
Silver is removed electrically from 200 ml of a 0.1 N solution of AgNO3 by a
current of 0.1 ampere. How long will it take to remove half of the silver from the
solution
[AMU 1999]
(a) 16 sec
(b) 96.5 sec
(c) 100 sec
(d) 10 sec
In order to separate oxygen from one mole of H2O the required quantity of
coulomb would be
[RPET 1999]
5
(a) 1.93 × 10
(b) 9.6 × 104
(c) 1.8
(d) 3.2
A current of 0.25A is passed through CuSO4 solution placed in voltameter for 45
minutes. The amount of Cu deposited on cathode is (At weight of Cu = 63.6)
[BHU 2001]
(a) 0.20 g
(b) 0.22 g
(c) 0.25 g
(d) 0.30 g
4 g of copper was dissolved in concentrated nitric acid. The copper nitrate solution on
strong heating gave 5 g of its oxide. The equivalent weight of copper is
[KCET 2004]
(a) 23
(b) 32
(c) 12
(d) 20
The amount of silver deposited by passing 241.25 coulomb of current through
silver nitrate solution is
[MH CET 2003]
(a) 2.7 g
(b) 2.7 mg
(c) 0.27 g
(d) 0.54 g
ELECTROCHEMISTRY
ANSWERSHEET
Que no. Ans.
1
c
2
b
3
b
4
a
5
d
6
c
7
d
8
a
9
c
10
b
11
b
12
a
13
c
14
d
15
d
16
a
17
a
18
d
19
c
20
c
21
b
22
b
23
a
24
b
25
c
26
a
27
b
28
a
29
d
30
a
31
b
32
a
33
b
34
a
35
a
36
a
37
c
34
Que no. Ans. Que no. Ans. Que no. Ans. Que no. Ans. Que no. Ans. Que no. Ans. Que no. Ans.
38
d
75
b
112
d
149
c
186
c
223
d
260
d
39
a
76
c
113
a
150
c
187
b
224
d
261
a
40
b
77
a
114
b
151
d
188
b
225
c
262
a
41
c
78
b
115
c
152
c
189
c
226
b
263
b
42
d
79
c
116
b
153
b
190
c
227
c
264
d
43
c
80
d
117
c
154
b
191
b
228
c
265
a
44
a
81
d
118
b
155
b
192
b
229
d
266
b
45
c
82
d
119
c
156
a
193
a
230
c
267
a
46
b
83
b
120
c
157
b
194
a
231
d
268
c
47
c
84
b
121
b
158
a
195
a
232
d
269
d
48
a
85
b
122
d
159
c
196
b
233
b
270
a
49
c
86
a
123
c
160
d
197
a
234
c
271
b
50
b
87
a
124
c
161
c
198
a
235
c
272
b
51
b
88
c
125
a
162
d
199
a
236
c
273
a
52
d
89
c
126
b
163
b
200
a
237
d
274
b
53
a
90
c
127
a
164
c
201
a
238
b
275
d
54
b
91
b
128
b
165
d
202
c
239
b
276
c
55
a
92
b
129
d
166
a
203
b
240
a
277
d
56
b
93
d
130
b
167
d
204
d
241
b
278
d
57
d
94
b
131
c
168
c
205
a
242
a
279
b
58
a
95
b
132
d
169
b
206
a
243
a
280
a
59
b
96
a
133
d
170
c
207
c
244
d
281
b
60
b
97
b
134
c
171
b
208
c
245
a
282
b
61
d
98
c
135
b
172
c
209
b
246
c
283
a
62
c
99
c
136
a
173
d
210
a
247
d
284
c
63
d
100
c
137
b
174
b
211
a
248
b
285
c
64
b
101
a
138
a
175
a
212
a
249
d
286
d
65
b
102
c
139
c
176
c
213
d
250
b
287
d
66
b
103
a
140
d
177
d
214
a
251
a
288
a
67
a
104
b
141
b
178
c
215
c
252
b
289
d
68
b
105
b
142
c
179
d
216
a
253
b
290
a
69
d
106
c
143
a
180
c
217
a
254
a
291
b
70
d
107
a
144
b
181
d
218
a
255
b
292
e
71
a
108
a
145
b
182
d
219
b
256
a
293
b
72
c
109
d
146
a
183
a
220
b
257
d
294
a
73
b
110
d
147
c
184
e
221
c
258
c
295
b
74
a
111
b
148
c
185
b
222
a
259
c
296
b
297
c

ELECTROCHEMISTRY WORKSHEET FOR JEE

Transcription

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