# Solved papers for NEET Chemistry NEET PYQ-Electrochemistry

### done NEET PYQ-Electrochemistry Total Questions - 45

• question_answer1) For the cell reaction,             $C{{u}^{2+}}({{C}_{1}}\,aq)+Zn(s)\rightleftharpoons Z{{n}^{2+}}({{C}_{2}}\,aq)+Cu(s)$ of an electrochemical cell. The change in free energy $(\Delta G)$ at a given temperature is a function of: [AIPMT 1998]

A)
In $({{C}_{1}})$

B)
In $({{C}_{2}}/{{C}_{1}})$

C)
In$({{C}_{2}})$

D)
In $({{C}_{1}}+{{C}_{2}})$

• question_answer2) Without losing its concentration $ZnC{{l}_{2}}$ solution cannot be kept in contact with:  [AIPMT 1998]

A)
Au

B)
Al

C)
Pb

D)
Ag

• question_answer3) The specific conductance of a 0.1 N KCl solution at $23{}^\circ C$ is $0.012\,\,oh{{m}^{-1}}c{{m}^{-1}}$. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be: [AIPMT 1999]

A)
$0.142\text{ }c{{m}^{-1}}$

B)
$0.66\text{ }c{{m}^{-1}}$

C)
$0.918\text{ }c{{m}^{-1}}$

D)
$1.12\text{ }c{{m}^{-1}}$

• question_answer4) The equivalent conductances of $B{{a}^{2+}}$ and $C{{l}^{-}}$  are 127 and 76 $oh{{m}^{-1}}\,\,c{{m}^{-1}}\,e{{q}^{-1}}$ respectively at infinite dilution. The equivalent conductance of $BaC{{l}_{2}}$ at infinite dilution will be: [AIPMT 2000]

A)
139.5

B)
203

C)
279

D)
101.5

• question_answer5) Cell reaction is spontaneous when: [AIPMT 2000]

A)
$E_{red}^{o}$            is negative

B)
$E_{red}^{o}$ is positive

C)
$\Delta {{G}^{o}}$ is negative

D)
$\Delta {{G}^{o}}$ is positive

• question_answer6)  $C{{u}^{+}}(aq)$ is unstable in solution and undergoes simultaneous oxidation and reduction according to the reaction: $2C{{u}^{+}}(aq)C{{u}^{2+}}(aq)+Cu(s)$ choose correct ${{E}^{o}}$ for above reaction if $E_{C{{u}^{2+}}/Cu}^{0}=0.34\,V$ and $E_{C{{u}^{2+}}/C{{u}^{+}}}^{0}=0.15\,V$ [AIPMT 2000]

A)
$\,0.38\text{ }V$

B)
$+\text{ }0.49\text{ }V$

C)
$+\text{ }0.38\text{ }V$

D)
$-\text{ }0.19\text{ }V$

• question_answer7)  Standard electrode potentials are: [AIPMT 2001] $F{{e}^{2+}}/Fe,$                 ${{E}^{o}}=-0.44$ $F{{e}^{3+}}/F{{e}^{2+}},$                       ${{E}^{o}}=0.77$ $F{{e}^{2+}},\,F{{e}^{3+}}$ and Fe block are kept together, then:

A)
$F{{e}^{3+}}$ increases

B)
$F{{e}^{3+}}$ decreases

C)
$\frac{F{{e}^{2+}}}{F{{e}^{3+}}}$ remains unchanged

D)
$F{{e}^{2+}}$ decreases

• question_answer8) The most convenient method to protect the bottom of ship made of iron is:   [AIPMT 2001]

A)
coating it with red lead oxide

B)
white tin plating

C)
connecting it with Mg block

D)
connecting it with Pb block

• question_answer9) In electrolysis of $NaCl$ when Pt electrode is taken then ${{H}_{2}}$ is liberated at cathode while with Hg cathode it forms sodium amalgam: [AIPMT 2002]

A)
Hg is more inert than Pt

B)
more voltage is required to reduce ${{H}^{+}}$ at Hg than at Pt

C)
Na is dissolved in Hg while it does not dissolved in Pt

D)
concentration of ${{H}^{+}}$ ions is larger when Pt electrode is taken

• question_answer10) The standard emf of a galvanic cell involving cell reaction with $n=2$ is found to be 0.295 V at $25{}^\circ \text{ }C$. The equilibrium constant of the reaction would be:                         [AIPMT (S) 2004] (Given: $F=96500\,\,C\,mo{{l}^{-1}};$$R=8.314\,J{{K}^{-1}}mo{{l}^{-1}})$

A)
$2.0\times {{10}^{11}}$

B)
$4.0\times {{10}^{12}}$

C)
$1.0\times {{10}^{2}}$

D)
$1.0\times {{10}^{10}}$

• question_answer11) The mass of carbon anode consumed (giving only carbondioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is:                                   [AIPMT (S) 2005]             (Atomic mass Al = 27)

A)
180 kg

B)
270 kg

C)
540 kg

D)
90 kg

• question_answer12) 4.5 g of aluminium (at. mass 27 amu) is deposited at cathode from  solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from  ions in solution by the same quantity of electric charge will be:                                [AIPMT (S) 2005]

A)
22.4 L

B)
44.8 L

C)
5.6 L

D)
11.2 L

• question_answer13) If $E_{F{{e}^{2+}}/Fe}^{o}=-0.441\,V$ and $E_{F{{e}^{3+}}/F{{e}^{2+}}}^{o}=0.771\,V,$ the standard emf of the reaction:   $Fe+2F{{e}^{3+}}\to ~3F{{e}^{2+}}$will be: [AIPMT (S) 2006]

A)
0.330 V

B)
1.653 V

C)
1.212 V

D)
0.111 V

• question_answer14)  A hypothetical electrochemical cell is shown below $A|{{A}^{+}}(xM)||{{B}^{+}}(yM)|B$. The emf measured is + 0.20 V. The cell reaction is:                                          [AIPMT (S) 2006]

A)
${{A}^{+}}+B\xrightarrow{{}}A+{{B}^{+}}$

B)
${{A}^{+}}+{{e}^{-}}\xrightarrow{{}}A;\,{{B}^{+}}+{{e}^{-}}\to B$

C)
the cell reaction cannot be predicted

D)
$A+{{B}^{+}}\xrightarrow{{}}{{A}^{+}}+B$

• question_answer15)  On the basis of the following $E{}^\circ$ values, the strongest oxidising agent is   [AIPMT (S) 2008] ${{[Fe{{(CN)}_{6}}]}^{4-}}\to {{[Fe{{(CN)}_{6}}]}^{3-}}]+{{e}^{-}};$${{E}^{o}}=-0.35V$ $F{{e}^{2+}}\to F{{e}^{3+}}+{{e}^{-}};{{E}^{o}}=-0.77V$

A)
${{[Fe{{(CN)}_{6}}]}^{4-}}$

B)
$F{{e}^{2+}}$

C)
$F{{e}^{3+}}$

D)
${{[Fe{{(CN)}_{6}}]}^{3-}}$

• question_answer16) Kohlrausch's law states that at [AIPMT (S) 2008]

A)
finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte

B)
in finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte depending on the nature of the other ion of the electrolyte.

C)
infinite dilution, each ion makes definite contribution to conductance of an electrolyte whatever be the nature of the other ion of the electrolyte.

D)
infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.

• question_answer17) Standard free energies of formation (in kJ/mol) at 298 K are $-237.2,\text{ }-394.4$ and $-8.2$ for${{H}_{2}}O(l)C{{O}_{2}}(g)$ ate) and pentane (g), respectively. The value of $E_{cell}^{o}$ pentane-oxygen fuel cell is                           [AIPMT (S) 2008]

A)
1.968 V

B)
2.0968 V

C)
1.0968 V

D)
0.0968 V

• question_answer18)  $A{{l}_{2}}{{O}_{3}}$ is reduced by electrolysis at low potentials and high currents. If $4.5\times {{10}^{4}}$ A of current is passed through molten $A{{l}_{2}}{{O}_{3}}$ for 6 h what mass of aluminium is produced?     [AIPMT (S) 2009] (Assume 100% current efficiency at. mass of $Al=27\,g\,mo{{l}^{-1}}$)

A)
$9.0\times {{10}^{3}}\,g$

B)
$8.1\times {{10}^{4}}\,g$

C)
$2.4\times {{10}^{5}}\,g$

D)
$1.3\times {{10}^{4}}\,g$

• question_answer19) The equivalent conductance of $\frac{M}{32}$ solution of a weak monobasic acid is $8.0\text{ }mho\text{ }c{{m}^{2}}$ and at infinite dilution is $400\text{ }mho\text{ }c{{m}^{2}}$. The dissociation constant of this acid is [AIPMT (S) 2009]

A)
$1.25\times {{10}^{-5}}$

B)
$1.25\times {{10}^{-6}}$

C)
$6.25\times {{10}^{-4}}$

D)
$1.25\times {{10}^{-4}}$

• question_answer20)  Given,                               [AIPMT (S) 2009] (i) $C{{u}^{2+}}+2{{e}^{-}}\xrightarrow[{}]{{}}Cu,$${{E}^{o}}=0.337\,V$ (ii) $C{{u}^{2+}}+{{e}^{-}}\xrightarrow[{}]{{}}C{{u}^{+}},$${{E}^{o}}=0.153\,V$ Electrode potential, ${{E}^{o}}$ for the reaction,  $Cu+{{e}^{-}}\xrightarrow[{}]{{}}Cu$, will be -

A)
0.52 V

B)
0.90 V

C)
0.30 V

D)
0.38 V

• question_answer21)  For the reduction of silver ions with copper metal, the standard cell potential was found to be $+\text{ }0.46\,V$ at $25{}^\circ C$ The value of standard Gibbs energy, $\Delta {{G}^{o}}$ will be $(F\text{ }=\text{ }96500\text{ }C\text{ }mo{{l}^{-1}})$    [AIPMT (S) 2010]

A)
$-89.0\text{ }kJ$

B)
$-89.0\text{ }J$

C)
$-44.5\text{ }kJ$

D)
$-98.0k\text{ }J$

• question_answer22) An increase in equivalent conductance of a strong electrolyte with dilution is mainly due  to [AIPMT (S) 2010]

A)
increase in ionic mobility of ions

B)
100% ionisation of electrolyte at normal dilution

C)
increase in both, i.e., number of ions and ionic mobility of ions

D)
increase in number of ions

• question_answer23) Which of the following expressions correctly represents the equivalent conductance at infinite dilution of $A{{l}_{2}}{{(S{{O}_{4}})}_{3}}$. Given that $\Lambda {{_{Al}^{o}}^{3+}}$ and $\Lambda _{SO_{4}^{2-}}^{o}$  are the equivalent conductances at infinite dilution of the respective ions?   [AIPMT (M) 2010]

A)
$2{{\Lambda }^{o}}_{A{{l}^{3+}}}+3{{\Lambda }^{o}}_{so\frac{2-}{4}}$

B)
${{\Lambda }^{o}}_{A{{l}^{3+}}}+{{\Lambda }^{o}}_{so\frac{2-}{4}}$

C)
$({{\Lambda }^{o}}_{A{{l}^{3+}}}+3{{\Lambda }^{o}}_{so\frac{2-}{4}})\times 6$

D)
$\frac{1}{3}{{\Lambda }^{o}}_{A{{l}^{3+}}}+\frac{1}{2}{{\Lambda }^{o}}_{so\frac{2-}{4}}$

• question_answer24)  Consider the following relations for emf of a electrochemical cell            [AIPMT (M) 2010] [A] Emf of cell = (oxidation potential of anode) (reduction potential of cathode) [B] Emf of cell = (oxidation potential of anode) + (reduction potential of cathode) [C] Emf of cell = (reduction potential of anode) + (reduction potential of cathode) [D] Emf of cell = (oxidation potential of anode)-(0xidation potential of cathode) Which of the above relations are correct?

A)
and

B)
and

C)
and

D)
None of these

• question_answer25) Standard electrode potential of three metals X, Y and Z are -1.2 V, + 0.5 V and -3.0 V respectively. The reducing power of these metal will be [AIPMT (S) 2011]

A)
$Y>X>Z$

B)
$Z>X>Y$

C)
$X>Y>Z$

D)
$Y>Z>X$

• question_answer26) If the ${{E}^{o}}_{cell}$ for a given reaction has a negative value then which of the following gives the correct relationships for the values of $\Delta {{G}^{o}}$ and ${{K}_{eq}}$? [AIPMT (S) 2011]

A)
$\Delta {{G}^{o}}<\,0;\,{{K}_{eq}}>1$

B)
$\Delta {{G}^{o}}<\,0;\,{{K}_{eq}}<1$

C)
$\Delta {{G}^{o}}>\,0;\,{{K}_{eq}}<1$

D)
$\Delta {{G}^{o}}>\,0;\,{{K}_{eq}}>1$

• question_answer27)  The electrode potentials for [AIPMT (S) 2011] $C{{u}^{2+}}(aq)+{{e}^{-}}\xrightarrow[{}]{{}}C{{u}^{+}}(aq)$ and$C{{u}^{+}}(aq)+{{e}^{-}}\xrightarrow[{}]{{}}Cu(s)$ Are + 0.15 V and + 0.50 v respectively. The value of ${{E}^{o}}_{C{{u}^{2+}}/Cu}$ will be

A)
0.325 V

B)
0.650 V

C)
0.150 V

D)
0.500 V

• question_answer28) Standard electrode potential for $S{{n}^{4+}}/S{{n}^{2+}}$ couple is +0.15 V and that for the $C{{r}^{3+}}/Cr$ couple is -0.74. These two couples in their standard state are connected to make a cell. The cell potential will be              [AIPMT (S) 2011]

A)
+ 0.89 V

B)
+ 0.18 V

C)
+ 1.83 V

D)
+ 1.199 V

• question_answer29) A solution contains $F{{e}^{2+}},F{{e}^{3+}}$ and ${{I}^{-}}$ ions. This solution was treated with iodine at $35{}^\circ C$. $E{}^\circ$ for $F{{e}^{3+}}/F{{e}^{2+}}$ is + 0.77 V and $E{}^\circ$ for ${{I}_{2}}/2{{I}^{-}}=0.536\,V$. The favorable redox reaction is                       [AIPMT (M) 2011]

A)
${{I}_{2}}$ will be reduced to ${{I}^{-}}$

B)
There will be no redox reaction

C)
${{I}^{-}}$ will be oxidised to ${{I}_{2}}$

D)
$F{{e}^{2+}}$ will be oxidised to $F{{e}^{3+}}$

• question_answer30) Limiting molar conductivity of $N{{H}_{4}}OH$ $(i.e.,\,\Delta {{m}_{(N{{H}_{4}}Cl)}})$ is equal to    [AIPMT (S) 2012]

A)
${{\Lambda }_{m(N{{H}_{4}}Cl)}}+{{\overset{o}{\mathop{\Lambda }}\,}_{m(NaCl)}}-{{\overset{o}{\mathop{\Lambda }}\,}_{m(NaOH)}}$

B)
${{\overset{o}{\mathop{\Lambda }}\,}_{m}}_{(NaOH)}+{{\overset{o}{\mathop{\Lambda }}\,}_{m(NaCl)}}-{{\overset{o}{\mathop{\Lambda }}\,}_{m(N{{H}_{4}}Cl)}}$

C)
${{\overset{o}{\mathop{\Lambda }}\,}_{m(N{{H}_{4}}OH)}}+{{\overset{o}{\mathop{\Lambda }}\,}_{m(N{{H}_{4}}Cl)}}-{{\overset{o}{\mathop{\Lambda }}\,}_{m(HCl)}}$

D)
${{\overset{o}{\mathop{\Lambda }}\,}_{m(N{{H}_{4}}OH)}}+{{\overset{o}{\mathop{\Lambda }}\,}_{m(NaOH)}}-{{\overset{o}{\mathop{\Lambda }}\,}_{m(NaCl)}}$

• question_answer31)  Standard reduction potentials of the half reactions are given below                    [AIPMT (M) 2012] ${{F}_{2}}(g)=2{{e}^{-}}\xrightarrow[{}]{{}}2{{F}^{-}}(aq);$${{E}^{o}}=+\,2.85\,V$$C{{l}_{2}}(g)+2{{e}^{-}}\xrightarrow[{}]{{}}2C{{l}^{-}}(aq);$${{E}^{o}}=+\,1.36\,V$ $B{{r}_{2}}(l)+2{{e}^{-}}\xrightarrow[{}]{{}}2B{{r}^{-}}(aq);$${{E}^{o}}=+1.06\,V$ ${{I}_{2}}(s)+2{{e}^{-}}\xrightarrow[{}]{{}}2{{I}^{-}}(aq);$${{E}^{o}}=+0.53\,V$ The strongest oxidsing and reducing agents respectively are

A)
${{F}_{2}}$ and ${{I}^{-}}$

B)
$B{{r}_{2}}$ and $C{{l}^{-}}$

C)
$C{{l}_{2}}$ and $B{{r}^{-}}$

D)
$C{{l}_{2}}$ and ${{I}_{2}}$

• question_answer32) Molar conductivities  at infinite dilution of  and   are 126.4, 425.9 and  respectively.  for  will be      [AIPMT (M) 2012]

A)

B)
$180.5\,\,S\,\,c{{m}^{2}}\,mo{{l}^{-1}}$

C)
$290.8\,\,S\,\,c{{m}^{2}}\,mo{{l}^{-1}}$

D)
$390.5\,\,S\,\,c{{m}^{2}}\,mo{{l}^{-1}}$

• question_answer33) A hydrogen gas electrode is made by dipping platinum wire in a solution of $HCl$ of $pH=10$ and by passing hydrogen gas around the platinum wire at 1 atm pressure. The oxidation potential of electrode would be        [NEET 2013]

A)
0.059 V

B)
0.59 V

C)
0.118 V

D)
1.18 V

• question_answer34) At $25{}^\circ C$ molar conductance of 0.1 molar aqueous   solution   of ammonium hydroxide is $9.54\,\,\,oh{{m}^{-1}}\,\,c{{m}^{2}}\,\,mo{{l}^{-1}}$ and at infinite dilution its molar conductance is $238\,\,oh{{m}^{-1}}\,c{{m}^{2}}\,mo{{l}^{-1}}$. The degree of ionization of ammonium hydroxide at the same concentration and temperature is [NEET 2013]

A)
2.080%

B)
20.800%

C)
4.008%

D)
40.800%

• question_answer35)  A button cell used in watches functions as following                                     [NEET 2013] $Zn(s)+A{{g}_{2}}O(s)+{{H}_{2}}O(l)2Ag(s)$$+Z{{n}^{2+}}(aq)+2O{{H}^{-}}(aq)$ If half cell potentials are $Z{{n}^{2+}}(aq)+2{{e}^{-}}\to Zn(s){{E}^{o}}=-0.76V$$A{{g}_{2}}O(s)+{{H}_{2}}O(l)+2{{e}^{-}}$$\to 2Ag(s)+2O{{H}^{-}}(aq),$${{E}^{o}}=0.34V$ The cell potential will be

A)
1.10 V

B)
0, 42 V

C)
0.84 V

D)
1.34 V

• question_answer36) The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of ${{O}_{2}}$ at STP will be                    [AIPMT 2014]

A)
5.4 g

B)
10.8 g

C)
54.0 g

D)
108.0 g

• question_answer37) A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as [NEET 2015 ]

A)
fuel cell

B)
electrolytic cell

C)
dynamo

D)
Ni-Cd cell

• question_answer38) 2, 3-dimethyl-2-butene can be prepared by heating which of the following compounds with a strong acid?                             [NEET 2015 (Re)]

A)
${{(C{{H}_{3}})}_{2}}CH-\underset{\underset{C{{H}_{3}}}{\mathop{|}}\,}{\mathop{CH}}\,-CH=C{{H}_{2}}$

B)
${{(C{{H}_{3}})}_{3}}C-CH=C{{H}_{2}}$

C)
${{(C{{H}_{3}})}_{2}}C=CH-C{{H}_{2}}-C{{H}_{3}}$

D)
${{(C{{H}_{3}})}_{2}}CH-C{{H}_{2}}-CH=C{{H}_{2}}$

• question_answer39) The pressure of ${{H}_{2}}$ required to make the potential of ${{H}_{2}}-$ electrode zero in pure water at 298 K is :-[NEET - 2016]

A)
${{10}^{14}}\text{ }atm$

B)
${{10}^{12}}\text{ }atm$

C)
${{10}^{-10}}atm$

D)
${{10}^{-4}}atm$

• question_answer40)  In the electrochemical cell [NEET-2017] $Zn|ZnS{{O}_{4}}(0.01)||CuS{{O}_{4}}(1.0\,M)Cu,$ the emf of this Daniel cell is ${{E}_{1}}$. When the concentration of $ZnS{{O}_{4}}$ is changed to 1.0 M and that of $CuS{{O}_{4}}$ changed to 0.01 M, emf changes to ${{E}_{2}}$. From the following, which one is the relationship between${{E}_{1}}$ and ${{E}_{2}}$? (Given, $\frac{RT}{F}=0.059$)

A)
${{E}_{2}}=0\ne {{E}_{1}}$

B)
${{E}_{1}}={{E}_{2}}$

C)
${{E}_{1}}<{{E}_{2}}$

D)
${{E}_{1}}>{{E}_{2}}$

• question_answer41)  Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below: [NEET - 2018] Then the species undergoing disproportionation is

A)
$\text{B}{{\text{r}}_{2}}$

B)
$\text{BrO}_{\text{4}}^{\text{-}}$

C)
$\text{BrO}_{\text{3}}^{\text{-}}$

D)
$\text{HBrO}$

• question_answer42)  For a cell involving one electron  $E_{cell}^{\Theta }=0.59\text{ }V\text{ }at\text{ }298\text{ }K$, the equilibrium constant for the cell reaction is: [Given that $\frac{2.303kT}{F}=0.059\text{ }V\text{ }at\text{ }T=298\text{ }K$] [NEET 2019]

A)
$1.0\times {{10}^{10}}$

B)
$1.0\times {{10}^{30}}$

C)
$1.0\times {{10}^{2}}$

D)
$1.0\times {{10}^{5}}$

• question_answer43)  For the cell reaction                      [NEET 2019] $2F{{e}^{3+}}(aq)+2{{I}^{}}(aq)\to 2F{{e}^{2+}}(aq)+{{I}_{2}}(aq)$$E_{cell}^{\Theta }\text{ }E=0.24\text{ }Vat\text{ }298\text{ }K$. The standard Gibbs energy $({{\Delta }_{r}}{{G}^{\Theta }})$ of the cell reaction is: [Given that Faraday constant$F=96500\text{ }C\text{ }mo{{l}^{1}}$]

A)
$46.32\text{ }kJ\text{ }mo{{l}^{1}}$

B)
$23.16\text{ }kJ\text{ }mo{{l}^{1}}$

C)
$-46.32\text{ }kJ\text{ }mo{{l}^{1}}$

D)
$-23.16\text{ }kJ\text{ }mo{{l}^{1}}$

• question_answer44)  The number of Faradays(F) required to produce 20 g of calcium from molten $CaC{{l}_{2}}$ (Atomic mass of$Ca=40\text{ }g\text{ }mo{{l}^{1}}$) is [NEET 2020]

A)
2

B)
3

C)
4

D)
1

• question_answer45) On electrolysis of dil. sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be[NEET 2020]

A)
Oxygen gas

B)
${{H}_{2}}S$ gas

C)
$S{{O}_{2}}$ gas

D)
Hydrogen gas