MCQOPTIONS
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MCQOPTIONS
This section includes 11242 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.
| 6351. |
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 |
| B. | Since (i) is less than (ii), zinc becomes the anode and iron the cathode |
| C. | Since (i) is more than (ii), zinc becomes the anode and iron the cathode |
| D. | Since (i) is more than (ii), zinc becomes the cathode and iron the anode |
| Answer» C. Since (i) is more than (ii), zinc becomes the anode and iron the cathode | |
| 6352. |
Which of the following metal does not react with the solution of copper sulphate [CPMT 1999] |
| A. | \[Mg\] |
| B. | \[Fe\] |
| C. | \[Zn\] |
| D. | \[Ag\] |
| Answer» E. | |
| 6353. |
(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. | \[Cu\,>\,Ag\,>\,Zn\] |
| B. | \[Ag\,>\,Cu\,>\,Zn\] |
| C. | \[Zn\,>\,Cu\,>\,Ag\] |
| D. | \[Cu\,>\,Zn\,>\,Ag\] |
| Answer» D. \[Cu\,>\,Zn\,>\,Ag\] | |
| 6354. |
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 |
| Answer» C. The standard reduction potential of iron is more than that of copper | |
| 6355. |
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 |
| B. | Oxidation occurs at \[Cu\] electrode |
| C. | Reduction occurs at \[{{H}_{2}}\] electrode |
| D. | \[{{H}_{2}}\] is anode; \[Cu\] is cathode |
| Answer» E. | |
| 6356. |
A standard hydrogen electrode has zero electrode potential because [IIT 1997] |
| A. | Hydrogen is easiest to oxidise |
| B. | The electrode potential is assumed to be zero |
| C. | Hydrogen atom has only one electron |
| D. | Hydrogen is the lightest element |
| Answer» C. Hydrogen atom has only one electron | |
| 6357. |
Which substance eliminates bromine from \[KBr\] solution [IIT 1981] |
| A. | \[{{I}_{2}}\] |
| B. | \[C{{l}_{2}}\] |
| C. | \[HI\] |
| D. | \[S{{O}_{2}}\] |
| Answer» C. \[HI\] | |
| 6358. |
The reaction is spontaneous if the cell potential is [MP PET 1999] |
| A. | Positive |
| B. | Negative |
| C. | Zero |
| D. | Infinite |
| Answer» B. Negative | |
| 6359. |
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 \[+0.45V\] |
| B. | Silver electrode is work like anode then \[E_{cell}^{o}\] is \[-0.34V\] |
| C. | Copper electrode is work like anode then \[E_{cell}^{o}\] is \[+0.46V\] |
| D. | Silver electrode is work like cathode then \[E_{cell}^{o}\] is \[-0.34V\] |
| E. | Silver electrode is work like anode then \[E_{cell}^{o}\] will be \[+1.14V\] |
| Answer» D. Silver electrode is work like cathode then \[E_{cell}^{o}\] is \[-0.34V\] | |
| 6360. |
Which of the following metal can deposit copper from copper sulphate solution [CPMT 1983; MP PMT 1989] |
| A. | Mercury |
| B. | Iron |
| C. | Gold |
| D. | Platinum |
| Answer» C. Gold | |
| 6361. |
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. | \[P>S>Q>R\] |
| Answer» E. | |
| 6362. |
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 |
| B. | < copper |
| C. | > sulphate |
| D. | < sulphate |
| Answer» C. > sulphate | |
| 6363. |
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 |
| B. | ? 0.404 V |
| C. | + 0.404 V |
| D. | + 0.771 V |
| Answer» E. | |
| 6364. |
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 |
| B. | More lead and \[F{{e}^{2+}}\]ions are formed |
| C. | Concentration of both \[P{{b}^{2+}}\]and \[F{{e}^{2+}}\]ions increases |
| D. | There is no net change |
| Answer» E. | |
| 6365. |
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 \[{{H}_{2}}\] |
| B. | \[Ag\] can oxidise \[{{H}_{2}}\] into \[{{H}^{+}}\] |
| C. | \[Z{{n}^{2+}}\] can be reduced by \[{{H}_{2}}\] |
| D. | \[Ag\] can reduce \[Z{{n}^{2+}}\] ion |
| Answer» B. \[Ag\] can oxidise \[{{H}_{2}}\] into \[{{H}^{+}}\] | |
| 6366. |
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 |
| B. | 1.36 V |
| C. | 2.7 V |
| D. | 2.03 V |
| Answer» D. 2.03 V | |
| 6367. |
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 |
| Answer» E. | |
| 6368. |
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 |
| B. | 0.42 V |
| C. | ? 1.1V |
| D. | ? 0.42 V |
| Answer» B. 0.42 V | |
| 6369. |
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 |
| B. | ? 0.58 V |
| C. | + 0.58 V |
| D. | ? 0.30 V |
| Answer» E. | |
| 6370. |
\[{{E}^{o}}\] 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 \[F{{e}^{2+}}\] |
| B. | \[Zn\] will reduce \[M{{g}^{2+}}\] |
| C. | \[Mg\] oxidises \[Fe\] |
| D. | \[Zn\] oxidises \[Fe\] |
| Answer» B. \[Zn\] will reduce \[M{{g}^{2+}}\] | |
| 6371. |
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. | \[Ag\] |
| B. | \[{{H}_{2}}\] |
| C. | \[Zn\] |
| D. | \[Li\] |
| Answer» E. | |
| 6372. |
If an iron rod is dipped in \[CuS{{O}_{4}}\] solution [MADT Bihar 1984] |
| A. | Blue colour of the solution turns green |
| B. | Brown layer is deposited on iron rod |
| C. | No change occurs in the colour of the solution |
| D. | Blue colour of the solution vanishes |
| E. | None of the above |
| Answer» C. No change occurs in the colour of the solution | |
| 6373. |
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. | \[Zn(s)\] |
| B. | \[Cr(s)\] |
| C. | \[{{H}_{2}}(g)\] |
| D. | \[F{{e}^{2+}}(aq)\] |
| Answer» B. \[Cr(s)\] | |
| 6374. |
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. | ? 0.25 \[V\] |
| D. | 0.25 \[V\] |
| Answer» E. | |
| 6375. |
The charge over anode in a galvanic cell is |
| A. | Negative |
| B. | Positive |
| C. | No charge |
| D. | Sometimes negative and sometimes positive |
| Answer» B. Positive | |
| 6376. |
The reference electrode is made from which of the following [MP PET/PMT 1988] |
| A. | \[ZnC{{l}_{2}}\] |
| B. | \[CuS{{O}_{4}}\] |
| C. | \[H{{g}_{2}}C{{l}_{2}}\] |
| D. | \[HgC{{l}_{2}}\] |
| Answer» D. \[HgC{{l}_{2}}\] | |
| 6377. |
Oxidation and reduction take place in a cell, then its electromotive force will be [RPET 1999] |
| A. | Positive |
| B. | Negative |
| C. | Zero |
| D. | Stable |
| Answer» B. Negative | |
| 6378. |
For a spontaneous reaction the \[\Delta G,\] equilibrium constant (K) and \[E_{Cell}^{o}\] will be respectively [AIEEE 2005] |
| A. | \[-ve,\,>1,\,+ve\] |
| B. | \[+ve,\,>1,\,-ve\] |
| C. | \[-ve,\,<1,\,-ve\] |
| D. | \[-ve,\,>1,\,-ve\] |
| Answer» B. \[+ve,\,>1,\,-ve\] | |
| 6379. |
\[EMF\]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 |
| B. | \[-\,1.75\,\,V\] |
| C. | + 1.75 V |
| D. | + 4.0 V |
| Answer» D. + 4.0 V | |
| 6380. |
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. | \[Cu>Zn>Mg>K\] |
| Answer» B. \[Mg>Zn>Cu>K\] | |
| 6381. |
\[K,\,\,Ca\] and \[Li\] metals may be arranged in the decreasing order of their standard electrode potentials as [CPMT 1990] |
| A. | \[K,\,\,Ca,\,\,Li\] |
| B. | \[Ca,\,\,K,\,\,Li\] |
| C. | \[Li,\,\,Ca,\,\,K\] |
| D. | \[Ca,\,\,Li,\,\,K\] |
| Answer» C. \[Li,\,\,Ca,\,\,K\] | |
| 6382. |
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 |
| B. | \[Zn\] is a reducing agent |
| C. | \[Zn\] is a oxidising agent |
| D. | \[Z{{n}^{2+}}\]is a reducing agent |
| Answer» C. \[Zn\] is a oxidising agent | |
| 6383. |
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 |
| B. | 0.036 V |
| C. | ? 1.562 V |
| D. | 0.799 V |
| Answer» B. 0.036 V | |
| 6384. |
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 |
| B. | \[B\] will deposit on \[A\] |
| C. | No reaction will occur |
| D. | Water will decompose into \[{{H}_{2}}\] and \[{{O}_{2}}\] |
| Answer» C. No reaction will occur | |
| 6385. |
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 |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 6386. |
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. | \[Hg\] |
| B. | \[Al\] |
| C. | \[Pb\] |
| D. | \[Fe\] |
| Answer» B. \[Al\] | |
| 6387. |
\[{{E}^{0}}=\frac{RT}{nF}\] In \[{{K}_{eq}}\]. This is called [CPMT 1988; MP PET 2000] |
| A. | Gibb's equation |
| B. | Gibb's?Helmholtz equation |
| C. | Nernst's equation |
| D. | Vander Waal's equation |
| Answer» D. Vander Waal's equation | |
| 6388. |
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. | \[{{M}_{1}}>{{M}_{2}}>{{M}_{3}}\] |
| B. | \[{{M}_{3}}>{{M}_{2}}>{{M}_{1}}\] |
| C. | \[{{M}_{1}}>{{M}_{3}}>{{M}_{2}}\] |
| D. | \[{{M}_{2}}>{{M}_{3}}>{{M}_{1}}\] |
| Answer» E. | |
| 6389. |
For the feasibility of a redox reaction in a cell, the e.m.f. should be [J & K 2002] |
| A. | Positive |
| B. | Fixed |
| C. | Zero |
| D. | Negative |
| Answer» B. Fixed | |
| 6390. |
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 |
| B. | 0.281 V |
| C. | 0.222 V |
| D. | 0.176 V |
| Answer» C. 0.222 V | |
| 6391. |
Which of the following expression is correct [Orissa JEE 2005] |
| A. | \[\Delta {{G}^{o}}=-nFE_{cell}^{o}\] |
| B. | \[\Delta {{G}^{o}}=+nFE_{cell}^{o}\] |
| C. | \[\Delta {{G}^{o}}=-2.303RT\,nFE_{cell}^{o}\] |
| D. | \[\Delta {{G}^{o}}=-nF\,\log {{K}_{C}}\] |
| Answer» B. \[\Delta {{G}^{o}}=+nFE_{cell}^{o}\] | |
| 6392. |
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 |
| B. | 0.83 volts |
| C. | 0.40 volts |
| D. | 0.45 volts |
| Answer» C. 0.40 volts | |
| 6393. |
When an acid cell is charged, then [AFMC 2005] |
| A. | Voltage of cell increases |
| B. | Electrolyte of cell dilutes |
| C. | Resistance of cell increases |
| D. | None of these |
| Answer» B. Electrolyte of cell dilutes | |
| 6394. |
The standard electrode potential is measured by [KCET 2005] |
| A. | Electrometer |
| B. | Voltmeter |
| C. | Pyrometer |
| D. | Galvanometer |
| Answer» C. Pyrometer | |
| 6395. |
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 |
| B. | -161 kJ mol-1 |
| C. | -152 kJ mol-1 |
| D. | -76 kJ mol-1 |
| Answer» B. -161 kJ mol-1 | |
| 6396. |
Standard electrode potential of \[NHE\] at 298 K is |
| A. | 0.05 V |
| B. | 0.1 V |
| C. | 0.00 V |
| D. | 0.11 V |
| Answer» D. 0.11 V | |
| 6397. |
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. | \[Fe\] |
| B. | Mn |
| C. | Cr |
| D. | Co |
| Answer» D. Co | |
| 6398. |
\[C{{r}_{2}}O_{7}^{2-}+{{I}^{-}}\to {{I}_{2}}+C{{r}^{3+}}\] \[{{E}^{0}}_{cell}=0.79\ V\] \[E_{C{{r}_{2}}O_{7}^{2-}}^{0}=1.33\ V,\ {{E}^{0}}_{{{I}_{2}}}\] is [BVP 2004] |
| A. | \[-0.10\ V\] |
| B. | \[+0.18\ V\] |
| C. | \[-0.54\ V\] |
| D. | \[0.54\ V\] |
| Answer» E. | |
| 6399. |
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 |
| B. | 1.40 V |
| C. | 1.68 V |
| D. | 0.63 V |
| Answer» B. 1.40 V | |
| 6400. |
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. | \[\frac{0.32}{{{e}^{0.0295}}}\] |
| B. | \[\frac{0.32}{{{10}^{0.0295}}}\] |
| C. | \[\frac{0.26}{{{10}^{0.0295}}}\] |
| D. | \[\frac{0.32}{{{10}^{0.0591}}}\] |
| Answer» C. \[\frac{0.26}{{{10}^{0.0295}}}\] | |