JEE Main & Advanced Chemistry Electrochemistry / विद्युत् रसायन Question Bank

done Electrode potential Ecell Nernst equation and ECS Total Questions - 129

• question_answer1)
  The hydrogen electrode is dipped in a solution of \[pH=3\] at \[{{25}^{o}}C\]. The potential of the cell would be (the value of \[2.303RT/F\]   is 0.059 V)            [KCET 1993,2005]
  A)
                  0.177 V done clear
  B)
                  ? 0.177 V done clear
  C)
                  0.087 V done clear
  D)
                  0.059 V done clear
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• question_answer2)
  The standard electrode potentials of \[Z{{n}^{2+}}/Zn\] and \[A{{g}^{+}}/Ag\] are \[-\,0.763\,V\] and \[+\,0.799\,V\] respectively. The standard potential of the cell is              [KCET 1993]
  A)
                  1.56 V    done clear
  B)
                  0.036 V done clear
  C)
                  ? 1.562 V              done clear
  D)
                  0.799 V done clear
  View Solution play_arrow

• question_answer3)
  The standard reduction potentials at \[298\,K\]for the following half reactions are given against each                 \[Z{{n}^{2+}}(aq.)+2e\]⇌\[Zn(s)\];      ? 0.762                 \[C{{r}^{3+}}(aq)+3e\]⇌\[Cr(s)\];         ? 0.740                 \[2{{H}^{+}}(aq)+2e\]⇌\[{{H}_{2}}(g)\];             0.00                 \[F{{e}^{3+}}(aq)+e\]⇌\[F{{e}^{2+}}(aq)\];     0.770                 Which is the strongest reducing agent [IIT 1981; MP PET/PMT 1988; MP PMT 1989;  MH CET 2001]
  A)
                  \[Zn(s)\]              done clear
  B)
                  \[Cr(s)\] done clear
  C)
                  \[{{H}_{2}}(g)\] done clear
  D)
                  \[F{{e}^{2+}}(aq)\] done clear
  View Solution play_arrow

• question_answer4)
  When \[Zn\] piece is kept in \[CuS{{O}_{4}}\] solution, the copper get precipitated due to standard potential of zinc is [CPMT 1999]
  A)
                  > copper              done clear
  B)
                  < copper done clear
  C)
                  > sulphate           done clear
  D)
                  < sulphate done clear
  View Solution play_arrow

• question_answer5)
  Which of the following metal does not react with the solution of copper sulphate             [CPMT 1999]
  A)
                  \[Mg\]  done clear
  B)
                  \[Fe\] done clear
  C)
                  \[Zn\]    done clear
  D)
                  \[Ag\] done clear
  View Solution play_arrow

• question_answer6)
  A solution containing one mole per litre of each \[Cu{{(N{{O}_{3}})}_{2}},\,\,AgN{{O}_{3}},\,\,H{{g}_{2}}{{(N{{O}_{3}})}_{2}}\] and \[Mg{{(N{{O}_{3}})}_{2}},\] is  being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are \[Ag/A{{g}^{+}}=+0.80,\,\,2Hg/Hg_{2}^{2+}=+0.79,\,\,Cu/C{{u}^{2+}}=+0.34,\]\[Mg/M{{g}^{2+}}=-2.37\]with increasing voltage,  the sequence of deposition of metals on the cathode will be [IIT 1984; AMU 1999; Kerala PMT 2004]
  A)
                  \[Ag,\,\,Hg,\,\,Cu,\,\,Mg\]          done clear
  B)
                  \[Mg,\,\,Cu,\,\,Hg,\,\,Ag\] done clear
  C)
                  \[Ag,\,\,Hg,\,\,Cu\]         done clear
  D)
                  \[Cu,\,\,Hg,\,\,Ag\] done clear
  View Solution play_arrow

• question_answer7)
  The standard reduction electrode potentials of four elements are                 \[A=-0.250\,\,V\]             \[B=-0.136\,V\]                 \[C=-0.126\,\,V\]             \[D=-0.402\,\,V\]                 The element that displaces A from its compounds is
  A)
                  B             done clear
  B)
                  C done clear
  C)
                  D             done clear
  D)
                  None of these done clear
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• question_answer8)
  The standard oxidation potential of zinc and silver in water at \[298\,\,K\]are                 \[Zn\,\,(s)\,\,\to \,\,Z{{n}^{2+}}+2{{e}^{-}}\,;\,E=0.76\,V\]                 \[Ag\,\,(s)\,\,\to \,A{{g}^{2+}}+2{{e}^{-}}\,;\,E=-0.80\,V\]                 Which of the following reactions actually take place                 [NCERT 1983, 84; KCET 2003]
  A)
                  \[Zn(s)+2A{{g}^{+}}(aq)\,\to \,Z{{n}^{++}}(aq)+2Ag(s)\] done clear
  B)
                  \[Z{{n}^{++}}(aq)+2Ag(s)\,\to \,2A{{g}^{+}}(aq)+Zn(s)\] done clear
  C)
                  \[Zn(s)+Ag(s)\,\to \,Z{{n}^{++}}(aq)+A{{g}^{+}}(aq)\] done clear
  D)
                  \[Z{{n}^{++}}(aq)+A{{g}^{+}}(aq)\,\to \,Zn(s)+Ag(s)\] done clear
  View Solution play_arrow

• question_answer9)
  Beryllium is placed above magnesium in the second group. Beryllium dust, therefore when added to \[MgC{{l}_{2}}\]solution will [CPMT 1977]
  A)
                  Have no effect done clear
  B)
                  Precipitate \[Mg\] metal done clear
  C)
                  Precipitate \[MgO\] done clear
  D)
                  Lead to dissolution of \[Be\]metal done clear
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• question_answer10)
  The name of equation showing relation between electrode potential \[(E)\]standard electrode potential \[({{E}^{o}})\] and concentration of ions in solution is
  A)
                  Kohlrausch's equation   done clear
  B)
                  Nernst's equation done clear
  C)
                  Ohm's equation                done clear
  D)
                  Faraday's equation done clear
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• question_answer11)
  The correct representation of Nernst's equation is
  A)
                  \[{{E}_{{{M}^{n+}}/M}}={{E}^{o}}_{{{M}^{n+}}/M}+\frac{0.0591}{n}\log \,({{M}^{n+}})\] done clear
  B)
                  \[{{E}_{{{M}^{n+}}/M}}={{E}^{o}}_{{{M}^{n+}}/M}-\frac{0.0591}{n}\log \,({{M}^{n+}})\] done clear
  C)
                  \[{{E}_{{{M}^{n+}}/M}}={{E}^{o}}_{{{M}^{n+}}/M}+\frac{n}{0.0591}\log \,({{M}^{n+}})\] done clear
  D)
                  None of the above done clear
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• question_answer12)
  Standard electrode potential of \[NHE\] at 298 K is
  A)
                  0.05 V    done clear
  B)
                  0.1 V done clear
  C)
                  0.00 V    done clear
  D)
                  0.11 V done clear
  View Solution play_arrow

• question_answer13)
  When a copper wire is placed in a solution of \[AgN{{O}_{3}}\], the solution acquires blue colour. This is due to the formation of [Roorkee 1989]
  A)
                  \[C{{u}^{2+}}\] ions done clear
  B)
                  \[C{{u}^{+}}\] ions done clear
  C)
                  Soluble complex of copper with \[AgN{{O}_{3}}\] done clear
  D)
                  \[C{{u}^{-}}\] ion by the reduction of \[Cu\] done clear
  View Solution play_arrow

• question_answer14)
  Consider the reaction \[M_{(aq)}^{n+}+n{{e}^{-}}\to {{M}_{(s)}}\]. The standard reduction potential values of the elements \[{{M}_{1}},\,{{M}_{2}}\] and \[{{M}_{3}}\] are \[-0.34V,\,-\,3.05\,V\] and \[-1.66\,V\] respectively. The order of their reducing power will be      [NCERT 1990]
  A)
                  \[{{M}_{1}}>{{M}_{2}}>{{M}_{3}}\]         done clear
  B)
                  \[{{M}_{3}}>{{M}_{2}}>{{M}_{1}}\] done clear
  C)
                  \[{{M}_{1}}>{{M}_{3}}>{{M}_{2}}\]         done clear
  D)
                  \[{{M}_{2}}>{{M}_{3}}>{{M}_{1}}\] done clear
  View Solution play_arrow

• question_answer15)
  \[{{E}^{0}}=\frac{RT}{nF}\] In \[{{K}_{eq}}\]. This is called [CPMT 1988; MP PET 2000]
  A)
                  Gibb's equation done clear
  B)
                  Gibb's?Helmholtz equation done clear
  C)
                  Nernst's equation done clear
  D)
                  Vander Waal's equation done clear
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• question_answer16)
  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 [MP PMT/PET 1988 ; CPMT 1983; MNR 1993; UPSEAT 2002]
  A)
                  A             done clear
  B)
                  B done clear
  C)
                  C             done clear
  D)
                  D done clear
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• question_answer17)
  Which one of the following metals cannot evolve \[{{H}_{2}}\]from acids or \[{{H}_{2}}O\] or from its compounds [MP PET/PMT 1988; CPMT 1996;  AFMC 1998, 99; Pb. PET 1999; BVP 2003]
  A)
                  \[Hg\]   done clear
  B)
                  \[Al\] done clear
  C)
                  \[Pb\]   done clear
  D)
                  \[Fe\] done clear
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• question_answer18)
  Which one of the following reaction is not possible [MP PMT 1991]
  A)
                  \[Fe+{{H}_{2}}S{{O}_{4}}\,\to \,\,FeS{{O}_{4}}+{{H}_{2}}\] done clear
  B)
                  \[Cu+2AgN{{O}_{3}}\,\to \,Cu\,{{(N{{O}_{3}})}_{2}}+2Ag\] done clear
  C)
                  \[2KBr+{{I}_{2}}\,\to \,\,2KI+B{{r}_{2}}\] done clear
  D)
                  \[CuO+{{H}_{2}}\,\to \,\,Cu+{{H}_{2}}O\] done clear
  View Solution play_arrow

• question_answer19)
  When a rod of metal \[A\] is dipped in an aqueous solution of metal \[B\](concentration of \[{{B}^{2+}}\]ion being 1M) at \[{{25}^{o}}C\], the standard electrode potentials are \[{{A}^{2+}}/A\]=?0.76 volts, \[{{B}^{2+}}\]/B = + 0.34 volts [KCET 1992]
  A)
                  \[A\] will gradually dissolve done clear
  B)
                  \[B\] will deposit on \[A\] done clear
  C)
                  No reaction will occur done clear
  D)
                  Water will decompose into \[{{H}_{2}}\] and \[{{O}_{2}}\] done clear
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• question_answer20)
   The reaction \[Z{{n}^{2+}}+2{{e}^{-}}\to Zn\] has a standard potential of \[-0.76\,V\]. This means            [KCET 1992]
  A)
                  \[Zn\] can't replace hydrogen from acids done clear
  B)
                  \[Zn\] is a reducing agent done clear
  C)
                  \[Zn\] is a oxidising agent done clear
  D)
                  \[Z{{n}^{2+}}\]is a reducing agent done clear
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• question_answer21)
  \[2{{H}^{+}}\,(aq)+2{{e}^{-}}\,\to \,{{H}_{2}}\,(g).\]The standard electrode potential for the above reaction is (in volts) [CPMT 1988]
  A)
                  0              done clear
  B)
                  + 1 done clear
  C)
                  ? 1          done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer22)
  \[K,\,\,Ca\] and \[Li\] metals may be arranged in the decreasing order of their standard electrode potentials as [CPMT 1990]
  A)
                  \[K,\,\,Ca,\,\,Li\]              done clear
  B)
                  \[Ca,\,\,K,\,\,Li\] done clear
  C)
                  \[Li,\,\,Ca,\,\,K\]              done clear
  D)
                  \[Ca,\,\,Li,\,\,K\] done clear
  View Solution play_arrow

• question_answer23)
  The correct order of chemical reactivity with water according to electrochemical series  [MP PMT 1991]
  A)
                  \[K>Mg>Zn>Cu\]             done clear
  B)
                  \[Mg>Zn>Cu>K\] done clear
  C)
                  \[K>Zn>Mg>Cu\]             done clear
  D)
                  \[Cu>Zn>Mg>K\] done clear
  View Solution play_arrow

• question_answer24)
  \[EMF\]of cell \[Ni\,\,|\,\,N{{i}^{2+}}\,(1.0\,M)\,\,||\,\,A{{u}^{3+}}\,(1.0\,M)\,\,|\,\,Au\] (Where \[{{E}^{o}}\] for \[N{{i}^{2+}}\,\,|\,\,Ni\] is \[-0.25\,\,V;\,\,{{E}^{o}}\] for \[A{{u}^{+3\,}}\,|\,\,Au\] is \[1.50\,\,V)\] is     [MP PET 1993; MP PMT 2000]
  A)
                  + 1.25 V                done clear
  B)
                  \[-\,1.75\,\,V\] done clear
  C)
                  + 1.75 V                done clear
  D)
                  + 4.0 V done clear
  View Solution play_arrow

• question_answer25)
  Oxidation and reduction take place in a cell, then its electromotive force will be                 [RPET 1999]
  A)
                  Positive                done clear
  B)
                  Negative done clear
  C)
                  Zero       done clear
  D)
                  Stable done clear
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• question_answer26)
  For a spontaneous reaction the \[\Delta G,\] equilibrium constant (K) and \[E_{Cell}^{o}\] will be respectively                   [AIEEE 2005]
  A)
                  \[-ve,\,>1,\,+ve\]            done clear
  B)
                  \[+ve,\,>1,\,-ve\] done clear
  C)
                  \[-ve,\,<1,\,-ve\]             done clear
  D)
                  \[-ve,\,>1,\,-ve\] done clear
  View Solution play_arrow

• question_answer27)
  The reference electrode is made from which of the following [MP PET/PMT 1988]
  A)
                  \[ZnC{{l}_{2}}\] done clear
  B)
                  \[CuS{{O}_{4}}\] done clear
  C)
                  \[H{{g}_{2}}C{{l}_{2}}\]  done clear
  D)
                  \[HgC{{l}_{2}}\] done clear
  View Solution play_arrow

• question_answer28)
  The charge over anode in a galvanic cell is
  A)
                  Negative done clear
  B)
                  Positive done clear
  C)
                  No charge done clear
  D)
                  Sometimes negative and sometimes positive done clear
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• question_answer29)
  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 \[V\]            done clear
  B)
                  ? 1.25 \[V\] done clear
  C)
                  ? 0.25 \[V\]         done clear
  D)
                  0.25 \[V\] done clear
  View Solution play_arrow

• question_answer30)
  The standard reduction potential for \[L{{i}^{+}}/Li\,;\,\,Z{{n}^{2+}}/Zn\,;\] \[{{H}^{+}}/{{H}_{2}}\] and \[A{{g}^{+}}/Ag\] is \[-3.05,\,\,-0.762,\,\,0.00\] and \[+0.80\,\,V.\] Which of the following has highest reducing capacity                                                [MP PMT 1992]
  A)
                  \[Ag\]   done clear
  B)
                  \[{{H}_{2}}\] done clear
  C)
                  \[Zn\]    done clear
  D)
                  \[Li\] done clear
  View Solution play_arrow

• question_answer31)
  If an iron rod is dipped in \[CuS{{O}_{4}}\] solution [MADT Bihar 1984]
  A)
                  Blue colour of the solution turns green done clear
  B)
                  Brown layer is deposited on iron rod done clear
  C)
                  No change occurs in the colour of the solution done clear
  D)
                  Blue colour of the solution vanishes done clear
  E)
                  None of the above done clear
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• question_answer32)
  \[{{E}^{o}}\] values of \[M{{g}^{2+}}/Mg\] is \[-2.37V\], of \[Z{{n}^{2+}}/Zn\] is \[-0.76V\] and \[F{{e}^{2+}}/Fe\] is \[-0.44\,V\]. Which of the following statements is correct  [EAMCET 1989]
  A)
                  \[Zn\] will reduce \[F{{e}^{2+}}\] done clear
  B)
                  \[Zn\] will reduce \[M{{g}^{2+}}\] done clear
  C)
                  \[Mg\] oxidises \[Fe\] done clear
  D)
                  \[Zn\] oxidises \[Fe\] done clear
  View Solution play_arrow

• question_answer33)
  The standard reduction potential for \[F{{e}^{2+}}/Fe\] and \[S{{n}^{2+}}/Sn\] electrodes are \[-0.44\] and \[-0.14\] volt respectively. For the given cell reaction \[F{{e}^{2+}}+Sn\,\to Fe+S{{n}^{2+}}\], the standard EMF is              [IIT Screening 1990; MP PMT 2003]
  A)
                  + 0.30 V                done clear
  B)
                  ? 0.58 V done clear
  C)
                  + 0.58 V                done clear
  D)
                  ? 0.30 V done clear
  View Solution play_arrow

• question_answer34)
  Electrode potential of \[Z{{n}^{2+}}/Zn\] is \[-0.76\,V\] and that of \[C{{u}^{2+}}/Cu\] is \[+0.34V\]. The EMF of the cell constructed between these two electrodes is [EAMCET 1992; BHU 2001; CBSE PMT 2001; KCET 1990;  MHCET 1999, 2003; Pb. CET 2002; AFMC 2001;  Pb. PMT 2004]
  A)
                  1.10 V    done clear
  B)
                  0.42 V done clear
  C)
                  ? 1.1V   done clear
  D)
                  ? 0.42 V done clear
  View Solution play_arrow

• question_answer35)
  EMF of a cell whose half cells are given below is                 \[M{{g}^{2+}}+2{{e}^{-}}\to Mg(s);\,\,E=-2.37\,V\]                 \[C{{u}^{2+}}+2{{e}^{-}}\to Cu(s);\,\,\,E=+0.33\,V\] [EAMCET 1987; MP PET 1994; Pb. PMT 2000]
  A)
                  ? 2.03 V                done clear
  B)
                  1.36 V done clear
  C)
                  2.7 V      done clear
  D)
                  2.03 V done clear
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• question_answer36)
  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         done clear
  B)
                  ? 3.04 volts done clear
  C)
                  + 2.36  volts done clear
  D)
                  ? 2.36 volts done clear
  View Solution play_arrow

• question_answer37)
  When \[E_{A{{g}^{+}}/Ag}^{o}=0.8\]volt and \[E_{Z{{n}^{2+}}/Zn}^{o}=-0.76\,\] volt, which of the following is correct                 [MP PMT 1994]
  A)
                  \[A{{g}^{+}}\] can be reduced by \[{{H}_{2}}\] done clear
  B)
                  \[Ag\] can oxidise \[{{H}_{2}}\] into \[{{H}^{+}}\] done clear
  C)
                  \[Z{{n}^{2+}}\] can be reduced by \[{{H}_{2}}\] done clear
  D)
                  \[Ag\] can reduce \[Z{{n}^{2+}}\] ion done clear
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• question_answer38)
  Adding powdered lead and iron to a solution that is 1.0 M in both \[P{{b}^{2+}}\]and \[F{{e}^{2+}}\]ions, would result a reaction, in which [CPMT 1987]
  A)
                  More iron and \[P{{b}^{2+}}\]ions are formed done clear
  B)
                  More lead and \[F{{e}^{2+}}\]ions are formed done clear
  C)
                  Concentration of both \[P{{b}^{2+}}\]and \[F{{e}^{2+}}\]ions increases done clear
  D)
                  There is no net change done clear
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• question_answer39)
  Given standard electrode potentials                 \[F{{e}^{++}}+2{{e}^{-}}\,\to \,Fe\,;\,\,\,\,{{E}^{o}}=-0.440\,\,V\]                 \[F{{e}^{+++}}+3{{e}^{-}}\,\to \,Fe\,;\,\,\,\,{{E}^{o}}=-0.036\,\,V\]                 The standard electrode potential \[({{E}^{o}})\] for                 \[F{{e}^{+++}}+{{e}^{-}}\to \,F{{e}^{++}}\] is                                      [AIIMS 1982]
  A)
                  ? 0.476 V              done clear
  B)
                  ? 0.404 V done clear
  C)
                  + 0.404 V              done clear
  D)
                  + 0.771 V done clear
  View Solution play_arrow

• question_answer40)
  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)
                  \[P>Q>R>S\]      done clear
  B)
                  \[Q>P>R>S\] done clear
  C)
                  \[R>Q>S>P\]      done clear
  D)
                  \[P>S>Q>R\] done clear
  View Solution play_arrow

• question_answer41)
  Which of the following metal can deposit copper from copper sulphate solution                [CPMT 1983; MP PMT 1989]
  A)
                  Mercury               done clear
  B)
                  Iron done clear
  C)
                  Gold      done clear
  D)
                  Platinum done clear
  View Solution play_arrow

• question_answer42)
  Standard electrode potential of \[A{{g}^{+}}/Ag\] and \[C{{u}^{+}}/Cu\] is \[+0.80V\] and \[+0.34V\] respectively. these electrodes are joint together by salt bridge if         [AMU 2002]
  A)
                  Copper electrode is work like cathode, then \[E_{cell}^{o}\] is \[+0.45V\] done clear
  B)
                  Silver electrode is work like anode then \[E_{cell}^{o}\] is \[-0.34V\] done clear
  C)
                  Copper electrode is work like anode then \[E_{cell}^{o}\] is \[+0.46V\] done clear
  D)
                  Silver electrode is work like cathode then \[E_{cell}^{o}\] is \[-0.34V\] done clear
  E)
                  Silver electrode is work like anode then \[E_{cell}^{o}\] will be  \[+1.14V\] done clear
  View Solution play_arrow

• question_answer43)
  The reaction is spontaneous if the cell potential is [MP PET 1999]
  A)
                  Positive                done clear
  B)
                  Negative done clear
  C)
                  Zero       done clear
  D)
                  Infinite done clear
  View Solution play_arrow

• question_answer44)
  Which substance eliminates bromine from \[KBr\] solution [IIT 1981]
  A)
                  \[{{I}_{2}}\]        done clear
  B)
                  \[C{{l}_{2}}\] done clear
  C)
                  \[HI\]    done clear
  D)
                  \[S{{O}_{2}}\] done clear
  View Solution play_arrow

• question_answer45)
  A standard hydrogen electrode has zero electrode potential because     [IIT 1997]
  A)
                  Hydrogen is easiest to oxidise done clear
  B)
                  The electrode potential is assumed to be zero done clear
  C)
                  Hydrogen atom has only one electron done clear
  D)
                  Hydrogen is the lightest element done clear
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• question_answer46)
  In the electrochemical cell                 \[{{H}_{2}}(g)\,1\,atm\,|{{H}^{+}}(1M)||C{{u}^{2+}}(1M)\,|Cu(s)\]                 Which one of the following statements is true [EAMCET 1997]
  A)
                  \[{{H}_{2}}\] is cathode; \[Cu\] is anode done clear
  B)
                  Oxidation occurs at \[Cu\] electrode done clear
  C)
                  Reduction occurs at \[{{H}_{2}}\] electrode done clear
  D)
                  \[{{H}_{2}}\] is anode; \[Cu\] is cathode done clear
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• question_answer47)
  Expression representing the cell potential \[(E\,\,cell)\]
  A)
                  Ecathode + Eanode    done clear
  B)
                  Eanode ? Ecathode done clear
  C)
                  Ecathode ? Eanode done clear
  D)
                  Eleft ? Eright done clear
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• question_answer48)
  Iron displaces copper from its salt solution, because [MP PMT 1996]
  A)
                  Atomic number of iron is less than that of copper done clear
  B)
                  The standard reduction potential of iron is less than that of copper done clear
  C)
                  The standard reduction potential of iron is more than that of copper done clear
  D)
                  The iron salt is more soluble in water than the copper salt done clear
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• question_answer49)
  (i) Copper metal dissolves in 1M silver nitrate solution and crystals of silver metal get deposited.                 (ii)           Silver metal does not react with 1 M 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
  A)
                  \[Cu\,>\,Ag\,>\,Zn\]      done clear
  B)
                   \[Ag\,>\,Cu\,>\,Zn\] done clear
  C)
                  \[Zn\,>\,Cu\,>\,Ag\]      done clear
  D)
                  \[Cu\,>\,Zn\,>\,Ag\] done clear
  View Solution play_arrow

• question_answer50)
  Standard electrode potentials of \[Zn\] and \[Fe\] are known to be (i) \[-0.76\,V\] and (ii) \[-0.44\,V\] respectively. How does it explain that galvanization prevents rusting of iron while zinc slowly dissolves away
  A)
                  Since (i) is less than (ii), zinc becomes the cathode and iron the anode done clear
  B)
                  Since (i) is less than (ii), zinc becomes the anode and iron the cathode done clear
  C)
                  Since (i) is more than (ii), zinc becomes the anode and iron the cathode done clear
  D)
                  Since (i) is more than (ii), zinc becomes the cathode and iron the anode done clear
  View Solution play_arrow

• question_answer51)
  Amongst the following electrodes the one with zero electrode potential is                                          [MP PMT 1997]
  A)
                  Calomel electrode done clear
  B)
                  Standard hydrogen electrode done clear
  C)
                  Glass electrode done clear
  D)
                  Gas electrode done clear
  View Solution play_arrow

• question_answer52)
  Which of the following is correct expression for electrode potential of a cell                                        [MP PMT 1997]
  A)
    \[E={{E}^{o}}-\frac{RT}{nF}\,\ln \,\frac{\text{ }\!\![\!\!\text{ product }\!\!]\!\!\text{ }}{\text{ }\!\![\!\!\text{ reactant }\!\!]\!\!\text{ }}\] done clear
  B)
   \[E={{E}^{o}}+\frac{RT}{F}\,\ln \,\frac{\text{ }\!\![\!\!\text{ product }\!\!]\!\!\text{ }}{\text{ }\!\![\!\!\text{ reactant }\!\!]\!\!\text{ }}\] done clear
  C)
    \[E={{E}^{o}}-\frac{RT}{nF}\,\ln \,\frac{\text{ }\!\![\!\!\text{ reactant }\!\!]\!\!\text{ }}{\text{ }\!\![\!\!\text{ product }\!\!]\!\!\text{ }}\] done clear
  D)
   \[E=-\frac{RT}{F}\ln \,\frac{\text{ }\!\![\!\!\text{ product }\!\!]\!\!\text{ }}{[\text{reactant }\!\!]\!\!\text{ }}\] done clear
  View Solution play_arrow

• question_answer53)
  Calculate standard free energy change for the reaction \[\frac{1}{2}Cu(s)+\frac{1}{2}C{{l}_{2}}(g)\]⇌\[\frac{1}{2}C{{u}^{2+}}+C{{l}^{-}}\] taking place at \[{{25}^{o}}C\] in a cell whose standard e.m.f. is 1.02 volts           [MP PMT 1997]
  A)
                  ? 98430 J              done clear
  B)
                  98430 J done clear
  C)
                  96500 J  done clear
  D)
                  ? 49215 J done clear
  View Solution play_arrow

• question_answer54)
  In which cell the free energy of a chemical reaction is directly converted into electricity ?              [MP PET/PMT 1998]
  A)
                  Leclanche cell    done clear
  B)
                  Concentration cell done clear
  C)
                  Fuel cell                done clear
  D)
                  Lead storage battery done clear
  View Solution play_arrow

• question_answer55)
  Nernst equation is related with
  A)
                  The electrode potential and concentration of ions in the solution done clear
  B)
                  Equilibrium constant and concentration of ions done clear
  C)
                  Free energy change and E.M.F. of the cell done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer56)
  The standard reduction potentials of 4 elements are given below. Which of the following will be the most suitable reducing agent I = ? 3.04 V, II = ? 1.90 V, III = 0 V, IV = 1.90 V [CPMT 1999]
  A)
                  I               done clear
  B)
                  II done clear
  C)
                  III            done clear
  D)
                  IV done clear
  View Solution play_arrow

• question_answer57)
  Electrode potential data are given below :                 \[F{{e}^{3+}}(aq)+{{e}^{-}}\to F{{e}^{-1}}(aq);\,{{E}^{o}}=+0.77V\]                 \[A{{l}^{3+}}(aq)+3{{e}^{-}}\to Al(s);\,{{E}^{o}}=-1.66V\]                 \[B{{r}_{2}}(aq)+2{{e}^{-}}\to 2B{{r}^{-}}(aq);\,{{E}^{o}}=+1.08\,V\]                 Based on the data given above, reducing power of \[F{{e}^{2+}},\,Al\] and \[B{{r}^{-}}\] will increase in the order                 [Pb. PMT 1998]
  A)
                  \[B{{r}^{-}}<F{{e}^{2+}}<Al\]      done clear
  B)
                  \[F{{e}^{2+}}<Al<B{{r}^{-}}\] done clear
  C)
                  \[Al<B{{r}^{-}}<F{{e}^{2+}}\]      done clear
  D)
                  \[Al<F{{e}^{2+}}<B{{r}^{-}}\] done clear
  View Solution play_arrow

• question_answer58)
  The standard electrode potential \[({{E}^{o}})\] for \[OC{{l}^{-}}/C{{l}^{-}}\] and \[C{{l}^{-}}/\frac{1}{2}C{{l}_{2}}\] respectively are \[0.94\,V\] and \[-1.36\,V\]. The \[{{E}^{o}}\] value for \[OC{{l}^{-}}/\frac{1}{2}C{{l}_{2}}\] will be                [KCET 1996]
  A)
                  \[-0.42\,V\]        done clear
  B)
                  \[-\,2.20\,V\] done clear
  C)
                  \[0.52\,V\]          done clear
  D)
                  \[1.04\,V\] done clear
  View Solution play_arrow

• question_answer59)
  If the reduction potential is more, then                 [CPMT 1996]
  A)
                  It is easily oxidised done clear
  B)
                  It is easily reduced done clear
  C)
                  It acts as oxidising agent done clear
  D)
                  It has redox nature done clear
  View Solution play_arrow

• question_answer60)
  One of the following is false for \[Hg\]   [BHU 1998]
  A)
                  It can evolve hydrogen from \[{{H}_{2}}S\] done clear
  B)
                  It is a metal done clear
  C)
                  It has high specific heat done clear
  D)
                  It is less reactive than hydrogen done clear
  View Solution play_arrow

• question_answer61)
  \[{{E}^{o}}\] for the cell \[Zn|Z{{n}^{2+}}(aq)||C{{u}^{2+}}(aq)|Cu\] is \[1.10\,V\] at \[{{25}^{o}}C\], the equilibrium constant for the reaction \[Zn+C{{u}^{2+}}(aq)\]⇌\[Cu+Z{{n}^{2+}}(aq)\] is of the order of [CBSE PMT 1997]
  A)
                  \[{{10}^{-28}}\]                 done clear
  B)
                  \[{{10}^{-37}}\] done clear
  C)
                  \[{{10}^{+18}}\]                done clear
  D)
                  \[{{10}^{+17}}\] done clear
  View Solution play_arrow

• question_answer62)
  Standard reduction potentials at \[{{25}^{o}}C\] of \[L{{i}^{+}}|Li,\,B{{a}^{2+}}|\,Ba,\,N{{a}^{+}}|\,Na\] and \[M{{g}^{2+}}|Mg\] are \[-3.05,\,-2.90,\,-2.71\] and \[-2.37\] volt respectively. Which one of the following is the strongest oxidising agent [CBSE PMT 1994; JIPMER 2002]
  A)
                  \[N{{a}^{+}}\]    done clear
  B)
                  \[L{{i}^{+}}\] done clear
  C)
                  \[B{{a}^{2+}}\]  done clear
  D)
                  \[M{{g}^{2+}}\] done clear
  View Solution play_arrow

• question_answer63)
  Which of the following displaces \[B{{r}_{2}}\] from an aqueous solution containing bromide ions [CBSE PMT 1994; JIPMER (Med.) 2002]
  A)
                  \[C{{l}_{2}}\]      done clear
  B)
                  \[C{{l}^{-}}\] done clear
  C)
                  \[{{I}_{2}}\]        done clear
  D)
                  \[I_{3}^{-}\] done clear
  View Solution play_arrow

• question_answer64)
  For the cell reaction                 \[C{{u}^{2+}}({{C}_{1}}aq)+Zn(s)=Z{{n}^{2+}}({{C}_{2}}aq)+Cu(s)\]                  of an electrochemical cell, the change in free energy at a given temperature is a function of                        [CBSE PMT 1998]
  A)
                  ln \[({{C}_{1}})\]               done clear
  B)
                  ln \[({{C}_{2}})\] done clear
  C)
                  ln \[({{C}_{1}}+{{C}_{2}})\]           done clear
  D)
                  ln \[({{C}_{2}}/{{C}_{1}})\] done clear
  View Solution play_arrow

• question_answer65)
  The e.m.f. of the cell in which the following reaction \[Zn(s)+N{{i}^{2+}}(a=1.0)\]⇌ \[Z{{n}^{2+}}(a=10)+Ni(s)\] 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   done clear
  B)
                  0.4810 V done clear
  C)
                  0.5696 V               done clear
  D)
                  ? 0.5105 V done clear
  View Solution play_arrow

• question_answer66)
  For the redox reaction \[Zn(s)+C{{u}^{2+}}(0.1M)\to Z{{n}^{2+}}(1M)+Cu(s)\] taking place in a cell, \[E_{cell}^{o}\] is 1.10 volt. \[{{E}_{cell}}\] for the cell will be \[\left( 2.303\frac{RT}{F}=0.0591 \right)\]                                       [AIEEE 2003]
  A)
                  2.14 volt               done clear
  B)
                  1.80 volt done clear
  C)
                  1.07 volt               done clear
  D)
                  0.82 volt done clear
  View Solution play_arrow

• question_answer67)
  The emf of a Daniel cell at 298K is \[{{E}_{1}}\]  \[Zn|\underset{(0.01\,\,M)}{\mathop{ZnS{{O}_{4}}}}\,||\underset{(1.0\,\,M)}{\mathop{CuS{{O}_{4}}}}\,|Cu\] when the concentration of \[ZnS{{O}_{4}}\] is 1.0 M and that of \[CuS{{O}_{4}}\] is 0.01 M, the emf changed to \[{{E}_{2}}\]. What is the relationship between \[{{E}_{1}}\] and \[{{E}_{2}}\]     [CBSE PMT 2003]
  A)
                  \[{{E}_{2}}=0\ne {{E}_{1}}\]         done clear
  B)
                  \[{{E}_{1}}>{{E}_{2}}\] done clear
  C)
                  \[{{E}_{1}}<{{E}_{2}}\]   done clear
  D)
                  \[{{E}_{1}}={{E}_{2}}\] done clear
  View Solution play_arrow

• question_answer68)
  The oxidation potentials of following half-cell reactions are given \[Zn\to Z{{n}^{2+}}+2{{e}^{-}};{{E}^{o}}=0.76\,\,V\],\[Fe\to F{{e}^{2+}}+2{{e}^{-}};{{E}^{o}}=0.44\,\,V\] what will be the emf of cell, whose cell-reaction is \[F{{e}^{2+}}(aq)+Zn\to Z{{n}^{2+}}(aq)+Fe\] [MP PMT 2003]
  A)
                  ? 1.20 V                done clear
  B)
                  + 0.32 V done clear
  C)
                  ? 0.32 V                done clear
  D)
                  + 1.20 V done clear
  View Solution play_arrow

• question_answer69)
  The \[{{E}^{o}}\] for half cells \[Fe/F{{e}^{2+}}\] and \[Cu/C{{u}^{2+}}\] are ? 0.44 V and  + 0.32 V respectively. Then                [MP PMT 2003]
  A)
                  \[C{{u}^{2+}}\]oxidises \[Fe\]    done clear
  B)
                  \[C{{u}^{2+}}\]oxidises \[F{{e}^{2+}}\] done clear
  C)
                  \[Cu\] oxidises \[F{{e}^{2+}}\]   done clear
  D)
                  \[Cu\] reduces \[F{{e}^{2+}}\] done clear
  View Solution play_arrow

• question_answer70)
  What is \[{{E}^{o}}\] for electrode represented by \[Pt,\,{{O}_{2}}(1\,atm)\,/\,2{{H}^{+}}(\operatorname{Im})\]                [JIPMER 1997]
  A)
                  Unpredictable   done clear
  B)
                  Zero done clear
  C)
                  0.018 V done clear
  D)
                  0.118 V done clear
  View Solution play_arrow

• question_answer71)
  The cell potential of a cell in operation is
  A)
                  Zero       done clear
  B)
                  Positive done clear
  C)
                  Negative              done clear
  D)
                  None of the above done clear
  View Solution play_arrow

• question_answer72)
  Which of the following is displaced by \[Fe\]       [Roorkee 1995]
  A)
                  \[Ag\]   done clear
  B)
                  \[Hg\] done clear
  C)
                  \[Zn\]    done clear
  D)
                  \[Na\] done clear
  View Solution play_arrow

• question_answer73)
  The standard electrode potential of the half cells are given below \[Z{{n}^{2+}}+2{{e}^{-}}\to Zn;E=-7.62\,\,V,\]\[F{{e}^{2+}}+2{{e}^{-}}\to Fe;E=-7.81\,\,V\] The emf of the cell \[F{{e}^{2+}}+Zn\to Z{{n}^{2+}}+Fe\] is [CPMT 2003]
  A)
                  1.54 V    done clear
  B)
                  ? 1.54 V done clear
  C)
                  ? 0.19 V                done clear
  D)
                  + 0.19 V done clear
  View Solution play_arrow

• question_answer74)
  \[Z{{n}^{2+}}+2{{e}^{-}}\to Zn(s);{{E}^{o}}=-\,0.76\],    \[F{{e}^{3+}}+{{e}^{-}}\to F{{e}^{2+}};{{E}^{o}}=-\,0.77\],\[C{{r}^{3+}}+3{{e}^{-}}\to Cr;{{E}^{o}}=-\,0.79\], \[{{H}^{+}}+2{{e}^{-}}\to 1/2{{H}_{2}}\,;\,{{E}^{o}}=0.00\] Strongest reducing agent is                                         [BHU 2003]
  A)
                  \[F{{e}^{2+}}\]  done clear
  B)
                  \[Zn\] done clear
  C)
                  \[Cr\]    done clear
  D)
                  \[{{H}_{2}}\] done clear
  View Solution play_arrow

• question_answer75)
  Standard reduction electrode potentials of three metals A, B and C are respectively + 0.5V, ? 3.0V and ? 1.2 V. The reducing powers of these metals are      [IIT 1998; AIEEE 2003]
  A)
                  B > C > A              done clear
  B)
                  A > B > C done clear
  C)
                  C > B > A              done clear
  D)
                  A > C > B done clear
  View Solution play_arrow

• question_answer76)
  For a cell reaction involving a two-electron change, the standard emf of the cell is found to be 0.295 V at \[{{25}^{o}}C\]. The equilibrium constant of the reaction at \[{{25}^{o}}C\] will be             [Roorkee 1999; AIEEE 2003; CBSE PMT 2004]
  A)
                  \[1\times {{10}^{-10}}\] done clear
  B)
                  \[29.5\times {{10}^{-2}}\] done clear
  C)
                  10           done clear
  D)
                  \[1\times {{10}^{10}}\] done clear
  View Solution play_arrow

• question_answer77)
  For the electrochemical cell, \[M|{{M}^{+}}||{{X}^{-}}|X,\]\[{{E}^{o}}({{M}^{+}}/M)\] = 0.44 V and \[{{E}^{o}}(X/{{X}^{-}})\]= 0.33 V. From this data one can deduce that [IIT-JEE (Screening) 2000]
  A)
                  \[M\,+\,X\,\to {{M}^{+}}+{{X}^{-}}\] is the spontaneous reaction done clear
  B)
                  \[{{M}^{+}}+{{X}^{-}}\to M+X\] is the spontaneous reaction done clear
  C)
                  \[{{E}_{cell}}\]= 0.77 V done clear
  D)
                  \[{{E}_{cell}}\]= ? 0.77 V done clear
  View Solution play_arrow

• question_answer78)
  The standard potential at \[{{25}^{o}}C\] for the following half reactions are given against them \[Z{{n}^{2+}}+2e\to Zn,{{E}^{o}}=-0.762V\]\[M{{g}^{2+}}+2e\to Mg,{{E}^{o}}=-2.37V\] When zinc dust is added to the solution of \[MgC{{l}_{2}}\]  [UPSEAT 2001]
  A)
                  \[ZnC{{l}_{2}}\]is formed done clear
  B)
                  Zinc dissolves in the solution done clear
  C)
                  No reaction takes place done clear
  D)
                  \[Mg\]is precipitated done clear
  View Solution play_arrow

• question_answer79)
  \[KMn{{O}_{4}}\] acts as an oxidising agent in the neutral medium and gets reduced to \[Mn{{O}_{2}}\]. The equivalent weight of \[KMn{{O}_{4}}\] in neutral medium [AMU 2001]
  A)
                  mol. wt/2            done clear
  B)
                  mol.wt/3 done clear
  C)
                  mol. wt/4            done clear
  D)
                  mol .wt/7 done clear
  View Solution play_arrow

• question_answer80)
  Which of the following condition will increase the voltage of the cell, represented by the equation \[C{{u}_{(s)}}+2A{{g}^{+}}_{(aq)}\to C{{u}^{2+}}_{(aq)}+2A{{g}_{(s)}}\]                [CBSE PMT 2001]
  A)
                  Increase in the concentration of \[A{{g}^{+}}\]ion done clear
  B)
                  Increase in the concentration of \[C{{u}^{+}}\] ion done clear
  C)
                  Increase in the dimension of silver electrode done clear
  D)
                  Increase in the dimension of copper electrode done clear
  View Solution play_arrow

• question_answer81)
  Which will increase the voltage of the cell \[S{{n}_{(s)}}+2A{{g}^{+}}_{(aq)}\to S{{n}^{2+}}_{(aq)}+2A{{g}_{(s)}}\]                [DPMT 2001]
  A)
                  Increase in the concentration of \[A{{g}^{+}}\]ions done clear
  B)
                  Increase in the concentration of \[S{{n}^{2+}}\]ions done clear
  C)
                  Increase in size of the silver rod done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer82)
  The mass of the proton is 1840 times that of electron, its potential difference is V. The kinetic energy of proton is [DCE 2001]
  A)
                  1840 KeV              done clear
  B)
                  1 KeV done clear
  C)
                  \[\frac{1}{1840}\] KeV    done clear
  D)
                  920 KeV done clear
  View Solution play_arrow

• question_answer83)
  What will be the emf for the given cell \[Pt|{{H}_{2}}({{P}_{1}})|{{H}^{+}}_{(aq)}||{{H}_{2}}({{P}_{2}})|Pt\]                        [AIEEE 2002]
  A)
                  \[\frac{RT}{f}\log \frac{{{P}_{1}}}{{{P}_{2}}}\]     done clear
  B)
                  \[\frac{RT}{2f}\log \frac{{{P}_{1}}}{{{P}_{2}}}\] done clear
  C)
                  \[\frac{RT}{f}\log \frac{{{P}_{2}}}{{{P}_{1}}}\]     done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer84)
  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    done clear
  B)
                  0.28 V done clear
  C)
                  0.38 V    done clear
  D)
                  0.48 V done clear
  View Solution play_arrow

• question_answer85)
  Will \[F{{e}_{(s)}}\]be oxidised to \[F{{e}^{2+}}\] by the reaction with 1 M \[HCl\]\[({{E}^{o}}\] for \[Fe/F{{e}^{2+}}\]= + 0.44 V)              [Pb. PMT 2000]
  A)
                  Yes         done clear
  B)
                  No done clear
  C)
                  May be done clear
  D)
                  Can?t say done clear
  View Solution play_arrow

• question_answer86)
  EMF of a cell in terms of reduction potential of its left and right electrodes is                                       [AIEEE 2002]
  A)
                  \[E={{E}_{left}}-{{E}_{right}}\]    done clear
  B)
                  \[E={{E}_{left}}+{{E}_{right}}\] done clear
  C)
                  \[E={{E}_{right}}-{{E}_{left}}\]    done clear
  D)
                  \[E=-({{E}_{right}}+{{E}_{left}})\] done clear
  View Solution play_arrow

• question_answer87)
  Arrange the following in the order of their decreasing electrode potential Mg, K, Ba, Ca                [JIPMER 2002]
  A)
                  \[K,Ba,Ca,Mg\] done clear
  B)
                  \[Ca,Mg,K,Ba\] done clear
  C)
                  \[Ba,Ca,K,Mg\] done clear
  D)
                  \[Mg,Ca,Ba,K\] done clear
  View Solution play_arrow

• question_answer88)
  Which of the following has highest electrode potential [Pb. PMT 2000]
  A)
                  \[Li\]      done clear
  B)
                  \[Cu\] done clear
  C)
                  \[Au\]   done clear
  D)
                  \[Al\] done clear
  View Solution play_arrow

• question_answer89)
  The cell reaction of a cell is                 \[M{{g}_{(s)}}+C{{u}^{2+}}(aq)\to C{{u}_{(s)}}+M{{g}^{2+}}(aq)\] If the standard reduction potentials of \[Mg\] and \[Cu\] are \[-\,2.37\] and \[+\,0.34\,V\] respectively. The emf of the cell is [EAMCET 1995; JIPMER (Med.) 2001; AFMC 2002; CBSE PMT 2002]
  A)
                  2.03 V    done clear
  B)
                  ? 2.03 V done clear
  C)
                  + 2.71 V                done clear
  D)
                  ? 2.71 V done clear
  View Solution play_arrow

• question_answer90)
  The element which can displace three other halogens from their compound is   [EAMCET 1998]
  A)
                  \[Cl\]     done clear
  B)
                  \[F\] done clear
  C)
                  \[Br\]    done clear
  D)
                  \[I\] done clear
  View Solution play_arrow

• question_answer91)
  Which of the following has been universally accepted as a reference electrode at all temperatures and has been assigned a value of zero volt       [AIIMS 1998]
  A)
                  Graphite electrode         done clear
  B)
                  Copper electrode done clear
  C)
                  Platinum electrode done clear
  D)
                  Standard hydrogen electrode done clear
  View Solution play_arrow

• question_answer92)
  Aluminium is more reactive than \[Fe\]. But \[Al\]is less easily corroded than iron because          [DCE 1999]
  A)
                  Al is noble metal               done clear
  B)
                  Iron forms both mono and divalent ions done clear
  C)
                  Oxygen forms a protective oxide layer done clear
  D)
                  Fe undergoes reaction easily with \[{{H}_{2}}O\] done clear
  View Solution play_arrow

• question_answer93)
  Zinc displaces copper from the solution of its salt because [MP PET 1995]
  A)
                  Atomic number of zinc is more than that of copper done clear
  B)
                  Zinc salt is more soluble in water than the copper salt done clear
  C)
                  Gibbs free energy of zinc is less than that of copper done clear
  D)
                  Zinc is placed higher than copper in electro-chemical series done clear
  View Solution play_arrow

• question_answer94)
  An electrochemical cell is set up as follows                 \[Pt({{H}_{2}},\,1\,atm)/0.1\,M\,HCl\]                 || 0.1 M acetic acid /( \[{{H}_{2}},\,1\,atm\]) Pt                 E.M.F. of this cell will not be zero because [CBSE PMT 1995]
  A)
                  The \[pH\] of 0.1 M HCl and 0.1 M  acetic acid is not the same done clear
  B)
                  Acids used in two compartments are different done clear
  C)
                  E.M.F. of a cell depends on the molarities of acids used done clear
  D)
                  The temperature is constant done clear
  View Solution play_arrow

• question_answer95)
  \[C{{u}^{+}}\] ion is not stable in aqueous solution because of disproportionation reaction. \[{{E}^{o}}\] value for disproportionation of \[C{{u}^{+}}\] is                 (Given \[E_{C{{u}^{2+}}/C{{u}^{+}}}^{o}=0.15\],  \[E_{C{{u}^{2+}}/Cu}^{o}=0.34V\])       [IIT 1995]
  A)
                  ? 0.49 V                done clear
  B)
                  0.49 V done clear
  C)
                  ? 0.38 V                done clear
  D)
                  0.38 V done clear
  View Solution play_arrow

• question_answer96)
  \[{{E}^{o}}\] of a cell \[aA+bB\to cC+dD\] is         [CPMT 1997]
  A)
                  \[-\frac{RT}{nF}\log \frac{{{[C]}^{c}}{{[D]}^{d}}}{{{[A]}^{a}}{{[B]}^{b}}}\]              done clear
  B)
                  \[-RT\,\log \frac{{{[a]}^{A}}{{[b]}^{B}}}{{{[a]}^{C}}{{[d]}^{D}}}\] done clear
  C)
                  \[-\frac{RT}{nF}\log \frac{{{[C]}^{c}}{{[d]}^{D}}}{{{[A]}^{a}}{{[B]}^{b}}}\]              done clear
  D)
                  \[-\frac{RT}{nF}\log \frac{{{[C]}^{c}}{{[d]}^{D}}}{{{[a]}^{A}}{{[B]}^{b}}}\] done clear
  View Solution play_arrow

• question_answer97)
  In the experiment set up for the measurement of EMF of a half cell using a reference electrode and a salt bridge, when the salt bridge is removed, the voltage [NCERT 1984; CPMT 1985]
  A)
                  Does not change done clear
  B)
                  Decreases to half the value done clear
  C)
                  Increase to maximum done clear
  D)
                  Drops to zero done clear
  View Solution play_arrow

• question_answer98)
  Electrode potentials of five elements \[A,\,B,\,C,\,D\] and \[E\] are respectively ? 1.36 , ? 0.32, 0, ? 1.26 and ?0.42. The reactivity order of these elements are in the order of [MP PMT 1995]
  A)
                  A, D, E, B and C  done clear
  B)
                  C, B, E, D and A done clear
  C)
                  B, D, E, A and C  done clear
  D)
                  C, A, E, D and B done clear
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• question_answer99)
  What is wrongly stated about electrochemical series  [DCE 1999]
  A)
                  It is the representation of element in order of increasing or decreasing standard electrode reductional potential done clear
  B)
                  It does not compare the relative reactivity of metals done clear
  C)
                  It compares relative strengths of oxidising agents done clear
  D)
                  \[{{H}_{2}}\] is centrally placed element done clear
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• question_answer100)
  Which of the following statements is true for fuel cells [KCET (Med.) 1999; AFMC 2000]
  A)
                  They are more efficient done clear
  B)
                  They are free from pollution done clear
  C)
                  They run till reactants are active done clear
  D)
                  All of these done clear
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• question_answer101)
  What is the potential of a half-cell consisting of zinc electrode in 0.01m \[ZnS{{O}_{4}}\] solution at \[{{258}^{o}}C\] \[({{E}^{o}}=0.763\,V)\] [AIIMS 2000; BHU 2000]
  A)
                  0.8221 V               done clear
  B)
                  8.221 V done clear
  C)
                  0.5282 V               done clear
  D)
                  9.232 V done clear
  View Solution play_arrow

• question_answer102)
  The emf of a galvanic cell, with electrode potentials of silver = +0.80V and that of copper = + 0.34 V, is [AIIMS 1999]
  A)
                  ? 1.1 V  done clear
  B)
                  + 1.1 V done clear
  C)
                  + 0.46 V                done clear
  D)
                  + 0.76 V done clear
  View Solution play_arrow

• question_answer103)
  Copper cannot replace?.. from solution                [DPMT 2002]
  A)
                  \[Fe\]    done clear
  B)
                  \[Au\] done clear
  C)
                  \[Hg\]   done clear
  D)
                  \[Ag\] done clear
  View Solution play_arrow

• question_answer104)
  The strongest reducing agent of the alkali metal is [CBSE PMT 2000]
  A)
                  \[Li\]      done clear
  B)
                  \[Na\] done clear
  C)
                  \[K\]      done clear
  D)
                  \[Cs\] done clear
  View Solution play_arrow

• question_answer105)
  Which of the following is the most electropositive element [Pb. PMT 2000]
  A)
                  Carbon done clear
  B)
                  Calcium done clear
  C)
                  Chlorine               done clear
  D)
                  Potassium done clear
  View Solution play_arrow

• question_answer106)
  The metal that forms a self protecting film of oxide to prevent corrosion, is         [BHU 1999]
  A)
                  \[Cu\]   done clear
  B)
                  \[Al\] done clear
  C)
                  \[Na\]   done clear
  D)
                  \[Au\] done clear
  View Solution play_arrow

• question_answer107)
  In a cell that utilises the reaction \[Z{{n}_{(s)}}+2{{H}^{+}}(aq)\to \] \[Z{{n}^{2+}}(aq)+{{H}_{ 2(g)}}\]addition of \[{{H}_{2}}S{{O}_{4}}\] to cathode compartment, will                                     [AIEEE 2004]
  A)
  Increase the E and shift equilibrium to the right done clear
  B)
  Lower the E and shift equilibrium to the right done clear
  C)
  Lower the E and shift equilibrium to the left done clear
  D)
  Increase the E and shift equilibrium to the left done clear
  View Solution play_arrow

• question_answer108)
  For the electrochemical cell, \[M|{{M}^{+}}||{{X}^{-}}|X,\] \[E{}^\circ ({{M}^{+}}|M)\]\[=0.44\ V\]\[E{}^\circ (X|{{X}^{-}})=0.33\ V\]From this data, one can deduce that                                         [Pb.CET 2004]
  A)
                  \[E{{{}^\circ }_{cell}}=-0.77\,V\] done clear
  B)
                  \[{{M}^{+}}+{{X}^{-}}\to M+X\] is the spontaneous reaction done clear
  C)
                  \[M+X\to {{M}^{+}}+{{X}^{-}}\]is the spontaneous reaction done clear
  D)
                  \[E{{{}^\circ }_{cell}}=.77\ V\] done clear
  View Solution play_arrow

• question_answer109)
  The standard e.m.f. of a call, involving one electron change is found to be \[0.591\ V\] at 25°C. The equilibrium constant of the reaction is (\[F=96,500\ C\ mo{{l}^{-1}};\] \[R=8.314\ J{{K}^{-1}}mo{{l}^{-1}})\] [AIEEE 2004]
  A)
                  \[1.0\times {{10}^{10}}\]              done clear
  B)
                  \[1.0\times {{10}^{5}}\] done clear
  C)
                  \[1.0\times {{10}^{1}}\] done clear
  D)
                  \[1.0\times {{10}^{30}}\] done clear
  View Solution play_arrow

• question_answer110)
  Standard electrode potential of cell \[{{H}_{2}}|{{H}^{+}}||A{{g}^{+}}|Ag\] is [AIEEE 2004]
  A)
                  0.8 V      done clear
  B)
                  ? 0.8 V done clear
  C)
                  ? 1.2 V  done clear
  D)
                  1.2 V done clear
  View Solution play_arrow

• question_answer111)
  A galvanic cell with electrode potential of \['A'=+2.23\ V\]and \['B'=-1.43\ V\]. The value of \[E{{{}^\circ }_{cell}}\] is                [Pb.CET 2003]
  A)
                  3.66 V    done clear
  B)
                  0.80 V done clear
  C)
                  ? 0.80 V                done clear
  D)
                  ? 3.66 V done clear
  View Solution play_arrow

• question_answer112)
  The e.m.f. of a cell whose half cells are given below is \[M{{g}^{2+}}+2{{e}^{-}}\to Mg(s)\ E{}^\circ =-2.37\ V\]\[C{{u}^{2+}}+2{{e}^{-}}\to Cu(s)\ E{}^\circ =+0.34\ V\]          [Pb.CET 2001]
  A)
                  + 1.36 V                done clear
  B)
                  + 2.71 V done clear
  C)
                  + 2.17 V                done clear
  D)
                  ? 3.01 V done clear
  View Solution play_arrow

• question_answer113)
  For the cell reaction, \[2C{{e}^{4+}}+Co\to 2C{{e}^{3+}}+C{{o}^{2+}}\] \[E{{{}^\circ }_{cell}}\]is 1.89 V. If \[E{{{}^\circ }_{C{{e}^{4+}}/C{{e}^{3+}}}}\]                   [Pb.CET 2000]
  A)
                  ? 1.64 V                done clear
  B)
                  + 1.64 V done clear
  C)
                  ? 2.08 V                done clear
  D)
                  + 2.17 V done clear
  View Solution play_arrow

• question_answer114)
  If the \[\Delta G\] of a cell reaction \[AgCl+{{e}^{-}}\to Ag+C{{l}^{-}}\] is \[-21.20\ KJ\]; the standard e.m.f., of cell is                    [MP PMT 2004]
  A)
                  0.229 V done clear
  B)
                  0.220 V done clear
  C)
                  ? 0.220 V              done clear
  D)
                  ? 0.110 V done clear
  View Solution play_arrow

• question_answer115)
  The e.m.f. of the cell \[Ag|A{{g}^{+}}(0.1M)||A{{g}^{+}}(1M)|Ag\] at 298 K is                                    [DCE 2003]
  A)
                  0.0059 V               done clear
  B)
                  0.059 V done clear
  C)
                  5.9 V      done clear
  D)
                  0.59 V done clear
  View Solution play_arrow

• question_answer116)
  The e.m.f. of the cell \[Zn|Z{{n}^{2+}}(0.01M)||F{{e}^{2+}}(0.001M)|Fe\] at 298 K is 0.2905 then the value of equilibrium for the cell reaction is             [IIT-JEE Screening  2004]
  A)
                  \[\frac{0.32}{{{e}^{0.0295}}}\]    done clear
  B)
                  \[\frac{0.32}{{{10}^{0.0295}}}\] done clear
  C)
                  \[\frac{0.26}{{{10}^{0.0295}}}\]  done clear
  D)
                  \[\frac{0.32}{{{10}^{0.0591}}}\] done clear
  View Solution play_arrow

• question_answer117)
  Aluminium displaces hydrogen from dilute HCl whereas silver does not. The e.m.f. of a cell prepared by combining \[Al/A{{l}^{3+}}\] and \[Ag/A{{g}^{+}}\]is  2.46 V. The reduction potential of silver electrode is \[+0.80\ V\]. The reduction potential of aluminium electrode is    [KCET  2004]
  A)
                  \[+1.66\ V\]        done clear
  B)
                  \[-3.26\,V\] done clear
  C)
                  \[3.26\ V\]          done clear
  D)
                  \[-1.66\ V\] done clear
  View Solution play_arrow

• question_answer118)
  Consider the following \[{{E}^{0}}\]values :                 \[{{E}^{0}}_{F{{e}^{3+}}/F{{e}^{2+}}}\] =\[+0.77\ V\]                 \[{{E}^{0}}_{S{{n}^{2+}}/Sn}=-0.14\ V\]                    Under standard conditions the potential for the reaction \[S{{n}_{(s)}}+2F{{e}^{3+}}(aq)\to 2F{{e}^{2+}}(sq)+S{{n}^{2+}}(aq)\] is      [AIEEE 2004]
  A)
                  0.91 V    done clear
  B)
                  1.40 V done clear
  C)
                  1.68 V    done clear
  D)
                  0.63 V done clear
  View Solution play_arrow

• question_answer119)
  \[C{{r}_{2}}O_{7}^{2-}+{{I}^{-}}\to {{I}_{2}}+C{{r}^{3+}}\]                 \[{{E}^{0}}_{cell}=0.79\ V\]                 \[E_{C{{r}_{2}}O_{7}^{2-}}^{0}=1.33\ V,\ {{E}^{0}}_{{{I}_{2}}}\] is                                              [BVP 2004]
  A)
                  \[-0.10\ V\]         done clear
  B)
                  \[+0.18\ V\] done clear
  C)
                  \[-0.54\ V\]         done clear
  D)
                  \[0.54\ V\] done clear
  View Solution play_arrow

• question_answer120)
  \[Zn(s)+C{{l}_{2}}(1\ \text{atm)}\to \text{Z}{{\text{n}}^{\text{2}+}}+2C{{l}^{-}}\]. \[{{E}^{0}}_{cell}\] of the cell is 2.12 V. To increase E                                 [BVP  2004]
  A)
                  \[[Z{{n}^{2+}}]\] should be increased done clear
  B)
                  \[[Z{{n}^{2+}}]\] should be decreased done clear
  C)
                  \[[C{{l}^{-}}]\]should be decreased done clear
  D)
                  \[{{P}_{C{{l}_{2}}}}\]should be decreased done clear
  View Solution play_arrow

• question_answer121)
  The \[{{E}^{0}}_{{{M}^{3+}}/{{M}^{2+}}}\]values for \[Cr,\ Mn,\ Fe\]and \[Co\]are \[-0.41,\ +1.57,\ +0.77\]and \[+1.97\ V\] respectively. For which one of these metals the change in oxidation state from \[+2\] to \[+3\]is easiest                                                [AIEEE 2004]
  A)
                  \[Fe\]    done clear
  B)
                  Mn done clear
  C)
                  Cr            done clear
  D)
                  Co done clear
  View Solution play_arrow

• question_answer122)
  The rusting of iron takes place as follows                 2H+  + 2e- + ½O2 \[\xrightarrow{{}}\] H2O(l) ;                  E° = +1.23 V                 Fe2+ + 2e- \[\xrightarrow{{}}\] Fe(s) ;  E° = -0.44 V                 Calculate DG° for the net process             [IIT 2005]
  A)
                  -322 kJ mol-1     done clear
  B)
                  -161 kJ mol-1 done clear
  C)
                  -152 kJ mol-1     done clear
  D)
                  -76 kJ mol-1 done clear
  View Solution play_arrow

• question_answer123)
  When an acid cell is charged, then            [AFMC 2005]
  A)
                  Voltage of cell increases               done clear
  B)
                  Electrolyte of cell dilutes done clear
  C)
                  Resistance of cell increases         done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer124)
  The standard electrode potential is measured by                                                                 [KCET 2005]
  A)
                  Electrometer     done clear
  B)
                  Voltmeter done clear
  C)
                  Pyrometer done clear
  D)
                  Galvanometer done clear
  View Solution play_arrow

• question_answer125)
  Aluminium displaces hydrogen from acids but copper does not. A galvanic cell prepared by combining \[Cu/C{{u}^{2+}}\]and \[Al/A{{l}^{3+}}\]has an e.m.f. of 2.0 V at 298 K. If the potential of copper electrode is  + 0.34 V, that of aluminium is                  [CPMT 2001; KCET 2001]
  A)
                  + 1.66 V                done clear
  B)
                  ? 1.66 V done clear
  C)
                  + 2.34 V                done clear
  D)
                  ? 2.3 V done clear
  View Solution play_arrow

• question_answer126)
  If the standard electrode potential of \[C{{u}^{2+}}/Cu\]  electrode is 0.34V, what is the electrode potential of 0.01M concentration of \[C{{u}^{2+}}\] \[(T=298\,K)\]                 [EAMCET 2003]
  A)
                  0.399 V done clear
  B)
                  0.281 V done clear
  C)
                  0.222 V done clear
  D)
                  0.176 V done clear
  View Solution play_arrow

• question_answer127)
  Calculate the electrode potential at \[{{298}^{o}}K\] for \[Zn|Z{{n}^{++}}\]electrode in which the activity of zinc ions is 0.001 M and \[{{E}^{o}}_{Zn/Z{{n}^{++}}}\]is ?0.74 volts            [AMU 2002]
  A)
                  0. 38 volts            done clear
  B)
                  0.83 volts done clear
  C)
                  0.40 volts             done clear
  D)
                  0.45 volts done clear
  View Solution play_arrow

• question_answer128)
  Which of the following expression is correct [Orissa JEE 2005]
  A)
                  \[\Delta {{G}^{o}}=-nFE_{cell}^{o}\]         done clear
  B)
                  \[\Delta {{G}^{o}}=+nFE_{cell}^{o}\] done clear
  C)
                  \[\Delta {{G}^{o}}=-2.303RT\,nFE_{cell}^{o}\]    done clear
  D)
                  \[\Delta {{G}^{o}}=-nF\,\log {{K}_{C}}\] done clear
  View Solution play_arrow

• question_answer129)
  For the feasibility of a redox reaction in a cell, the e.m.f. should be          [J & K  2002]
  A)
                  Positive   done clear
  B)
                  Fixed done clear
  C)
                  Zero       done clear
  D)
                  Negative done clear
  View Solution play_arrow