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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1051. |
In s salt bridge, KCl is used becauseA. it is and electrolyteB. KCl is found in pure crystalline state in large depositsC. it is a good conductor of electricityD. it forms a good jelly with agr-agr. |
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Answer» Correct Answer - A::C::D (a,c,d) are correct. |
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| 1052. |
Other things being equal , the EMF of a Daniel cell may be increased byA. keeping low temperatureB. using large copper electrodesC. using large zinc electrodesD. decreasing concentration of `Cu^(2+)` ions . |
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Answer» Correct Answer - A For Daniel cell , `Zn + Cu^(2+) to Zn^(2+) + Cu` , `E_("cell") = E_("cell")^(@) - (RT)/(nF) "ln" ([Zn^(2+)])/([Cu^(2+)])` . Decrease of temperature and increase of `[Cu^(2+)]` will increase the EMF . |
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| 1053. |
KCl, `KNO_(3)` etc. are preferred in a salt bridge because they have equal____. |
| Answer» Correct Answer - Transport number | |
| 1054. |
The electrode reaction (reduction reaction) occurring in the calomel electrode is______. |
| Answer» `Hg_(2)Cl_(2)(s)+2e^(-)to2Hg(l)+2Cl^(-)(aq)` | |
| 1055. |
Assertion In the equation `HCl+H_(2)OhArrH_(3)O^(+)+Cl^(-)` HCl is a strong acid and `Cl^(-)` is a weak base while in the equation `CH_(3)COOH+H_(2)OhArrCH_(3)COO^(-)+H_(3)O^(+)` `CH_(3)COOU` is a weak acid and `CH_(3)` and `CH_(3)COO^(-)`is a strong base. Reason The stronger an acid, the weaker must be its base and vice-versa.A. Both A and R are true and R is the correct explanation of AB. Both A and R are true but R is not a correct explanation of AC. A is true but R is falseD. Both A and R are false. |
| Answer» Correct Answer - A | |
| 1056. |
A current of 1.50 A was passed through an electrolytic cell containing `AgNO_(3)` solution with inert electrodes. The mass of the silver deposited at cathode was 1.50 g. How long did the current flow? (Atomic mass of Ag=108u, F=96500C). |
| Answer» Correct Answer - 893.5 s | |
| 1057. |
An electric current is passed through silver nitrated solution using silver electrodes . ` 10. 79 g` of silver qas found to be deposited on the cathode fi the same amount of electricity is passed through copper sulphate solutin using copper electrodes. the weihgt of copper deposited on teh cathode is .A. 6.4gB. 2.3gC. 12.8gD. 3.2g |
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Answer» Correct Answer - D `("Wt of Ag")/("Wt. of Cu")=("Eq. wt of Ag")/("Eq. wt. of Cu")` `(10.79)/(m(Cu))-(107.9)/(63.5//2)` (at mass of Cu=63.5, At, mass of Ag=107.0) `m(Cu)=(10.79)/(107.9)-(63.5)/(2)=3.175g` |
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| 1058. |
For hydrogen oxygen fuel cell with reaction `2H_(2)(g)+O_(2)(g) rarr 2 H_(2)O(l)` `DeltaG_(f)^(c-)(H_(2)O)=-237.2kJ mol^(-1)`. Hence, `EMF` of the fuel cell isA. `+2.46 V`B. `-2.46V`C. `+1.23 V`D. `-1.23V` |
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Answer» Correct Answer - c Fuel cell reaction is `:` `2H_(2)(g)+O_(2)(g) rarr 2H_(2)O(l)` At anode `: 2H_(2)(g)+4overset(c-)(O)H(aq) rarr 4H_(2)O+4e^(-)` `(` Half oxidation `)` At cathode `:` `O_(2)(g)+2H_(2)O(l)+4e^(-)rarr 4 overset(c-)(O)H(aq)` `(` Half reduction `)` `ulbar(Cell reaction : 2H_(2)(g)+O_(2)(g)rarr2H_(2)O(l))` `:. n_(cell)=4` `Delta_(r)G^(c-)=2Delta_(f)G^(c-)._((H_(2)o))-2Delta_(f)G^(c-)._((H_(2)O))-2Delta_(f)G^(c-)._((O_(2)))` `=2(-237.2)kJ mol^(-1)-2xx0-0` `=2(-237.2k J mol^(-1)` `Delta_(r)G^(c-)=-nFE^(c-)._(cell)` `2(-237.2)kJ mol^(-1)=-4xx96500CxxE^(c-)._(cell)` `:. E^(c-)._(cell)=1.23V` |
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| 1059. |
The standard reduction potential for `Zn^(2+)//Zn, Ni^(2+)//Ni` and `Fe^(2+)//Fe` are -0.76,-0.23 and `-0.44" V "` respectively. The reaction `X+Y^(2+) to X^(2)+Y` will have more negative `DeltaG` value when X and Y areA. X=Ni, Y=FeB. X=Ni , Y=ZnC. X=Fe , Y=ZnD. X=Zn , Y=Ni |
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Answer» Correct Answer - D (d) `X+Y^(2+) to X^(2+)+Y` `DeltaG=-nFE_(cell)`. Greater the value of `E_(cell)`.more will be the value of `DeltaG`. For this, the difference between `E^(@)` values of `X^(2+)` and `Y^(2+)` must be maximum. This means that X=Zn and Y=Ni. |
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| 1060. |
A secondary cell is one :A. Can be rechargedB. Can be recharged by passing current through it in the same directionC. Can be recharged by passing current through it in the opposite directionD. Cannot be recharged. |
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Answer» Correct Answer - C (c ) It is the correct answer, |
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| 1061. |
The concentration of potassium ions inside a biological cell is at least 20 times higher than outside. The resulting potential difference across the cell is important in several processes such as transmission of nerve impulses and maintaining the ion balance. A simplel model for a concentration cell involving a metal `M` is `M(s)|M^(o+)(aq,0.05 ` molar`)||M^(o+)(aq,1` molar`)|M(s)` For the abov electrolytic cell, the magnitude of the cell potential is `|E_(cell)|=70mV.` If the `0.05` moolar solution of `M^(o+)` is replaced by a `0.0025` molar `M^(o+)` solution, then the magnitude of the cell potential would beA. 35 m VB. 70 m VC. 140 m VD. 700 m V |
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Answer» Correct Answer - C From the above quation , `(2.303 RT)/(F) "log" (1)/(0.05) = 70 m V = 70 xx 10^(-3) V = 0.07 V ` `therefore (2.303 RT)/(F) = (0.07)/(1.301) = 0.0538` V For the new concentration , `E_(cell) = (2.303 RT)/(F) "log" (1)/(0.0025)` `= 0.0538 log 400 = 0.0538 xx 2.6021V` = `0.140 V = 140 m V ` |
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| 1062. |
The concentration of potassium ions inside a biological cell is at least 20 times higher than outside. The resulting potential difference across the cell is important in several processes such as transmission of nerve impulses and maintaining the ion balance. A simplel model for a concentration cell involving a metal `M` is `M(s)|M^(o+)(aq,0.05 ` molar`)||M^(o+)(aq,1` molar`)|M(s)` For the abov electrolytic cell, the magnitude of the cell potential is `|E_(cell)|=70mV.` For the above cellA. `E_(cell)lt0,DeltaGgt0`B. `E_(cell)gt0,DeltaGlt0`C. `E_(cell)lt0,DeltaG^(c-)gt0`D. `E_(cell)gt0,DeltaG^(c-)lt0` |
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Answer» Correct Answer - b `M(s)+M^(o+)(1M) rarr M^(o+)(0.5M)+M(s)` `E^(c-)._(cell)=0(` For concentratin cell `)` `E_(cell)=E^(c-)._(cell)-(2.303RT)/(F)log.([M^(o+)]_((0.5M)))/([M^(o+)]_((1M)))` `=0-(2.303RT)/(F)log(5xx10^(-2)) …..(i)` `=+ve` Hence, `|E_(cell)|=E_(cell)=70mV` and `DeltaGlt0` for the feasiblity of the reaction. |
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| 1063. |
Redox reactions play a pivotal role in chemistry and biology. The values standard redox potential `(E^(c-))` of two half cell reactions decided which way the reaction is expected to preceed. A simple example is a Daniell cell in which zinc goes into solution and copper sets deposited. Given below are a set of half cell reactions `(` acidic medium `)` along with their `E^(c-)(V` with respect to normal hydrogen electrode `)` values. Using this data, obtain correct explanations for Question. `I_(2)+2e^(-) rarr 2I^(c-)," "E^(c-)=0.54` `Cl_(2)+2e^(-) rarr 2Cl^(c-), " "E^(c-)=1.36` `Mn^(3+)+e^(-) rarr Mn^(2+), " "E^(c-)=1.50` `Fe^(3+)+e^(-) rarr Fe^(2+)," "E^(c-)=0.77` `O_(2)+4H^(o+)+4e^(-) rarr 2H_(2)O, " "E^(c-)=1.23` Sodium fusion extract obtained from aniline on treatment with iron `(II)` sulphate and `H_(2)SO_(4)` in the presence of air gives a Prussion blue precipitate. The blue colour is due to the formation ofA. `Fe_(4)[Fe(CN)_(6)]_(3)`B. `Fe_(3)[Fe(CN)_(6)]_(2)`C. `Fe_(4)[Fe(CN)_(6)]_(2)`D. `Fe_(3)[Fe(CN)_(6)]_(3)` |
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Answer» Correct Answer - a `Na+C+Nrarr underset(Sodium extract)(NaCN)` `Fe^(2+)+6CN^(c-)rarr [Fe(CN)_(6)]^(4-)` `4Fe^(3+)+3[Fe(CN)_(6)]^(4-)rarr underset(Prussai n bl ue ppt )(Fe_(4)[Fe(CN)_(6)]_(3)` |
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| 1064. |
Redox reactions play a pivotal role in chemistry and biology. The values standard redox potential `(E^(c-))` of two half cell reactions decided which way the reaction is expected to preceed. A simple example is a Daniell cell in which zinc goes into solution and copper sets deposited. Given below are a set of half cell reactions `(` acidic medium `)` along with their `E^(c-)(V` with respect to normal hydrogen electrode `)` values. Using this data, obtain correct explanations for Question. `I_(2)+2e^(-) rarr 2I^(c-)," "E^(c-)=0.54` `Cl_(2)+2e^(-) rarr 2Cl^(c-), " "E^(c-)=1.36` `Mn^(3+)+e^(-) rarr Mn^(2+), " "E^(c-)=1.50` `Fe^(3+)+e^(-) rarr Fe^(2+)," "E^(c-)=0.77` `O_(2)+4H^(o+)+4e^(-) rarr 2H_(2)O, " "E^(c-)=1.23` While `Fe^(3+)` is stable, `Mn^(3+)` is not stable in acid solution becauseA. `O_(2)` oxidizes `Mn^(2+)` to `Mn^(3+)`B. `O_(2)` oxidizes both `Mn^(2+)` to `Mn^(3+)` and `Fe^(2+)` to `Fe^(3+)`C. `Fe^(3+)` oxidizes `H_(2)O` to `O_(2)`D. `Mn^(3+)` oxidized `H_(2)O` to `O_(2)` |
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Answer» Correct Answer - d `[Mn^(3+)+e^(-) rarr Mn^(2+)]xx4` `2H_(2)Orarr H^(o+)+O_(2)+4e^(-)` `ulbar(4Mn^(2+)+2H_(2)Orarr 4Mn^(2+)+4H^(o+)+O_(2))` `(E^(c-)._(cell)`is `+ve)` |
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| 1065. |
Redox reactions play a pivotal role in chemistry and biology. The values standard redox potential `(E^(c-))` of two half cell reactions decided which way the reaction is expected to preceed. A simple example is a Daniell cell in which zinc goes into solution and copper sets deposited. Given below are a set of half cell reactions `(` acidic medium `)` along with their `E^(c-)(V` with respect to normal hydrogen electrode `)` values. Using this data, obtain correct explanations for Question. `I_(2)+2e^(-) rarr 2I^(c-)," "E^(c-)=0.54` `Cl_(2)+2e^(-) rarr 2Cl^(c-), " "E^(c-)=1.36` `Mn^(3+)+e^(-) rarr Mn^(2+), " "E^(c-)=1.50` `Fe^(3+)+e^(-) rarr Fe^(2+)," "E^(c-)=0.77` `O_(2)+4H^(o+)+4e^(-) rarr 2H_(2)O, " "E^(c-)=1.23` Among the following, identify the correct statement.A. Chloride ion is oxidized by `O_(2)`.B. `Fe^(2+)` is oxidized by iodine.C. Iodide ion is oxidized by chlorineD. `Mn^(2+)` is oxidized by chlorine. |
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Answer» Correct Answer - c `2I^(c-)+Cl_(2) rarr I_(2)+2Cl^(c-),E^(c-)._(cell)=1.36-0.54=0.82V` `E^(c-)._(cell)` is `+ve` . Thus, the cell reaction is feasible. |
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| 1066. |
When acidulated water (dil. `H_(2)SO_(4)` solution) is electrolysed, with pH of the solution be affected? Justify your answer. |
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Answer» Since pH of solution depends upon concentration of `H^(+)` presence in solution. pH of the solution will not be affected as `[H^(+)]` remains constant At anode `2H_(2)Orarr O_(2)+4H^(+)+4e^(-)` At cathode `4H^(-)+4e^(-)rarr2H_(2)` |
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| 1067. |
Chemical reactions involve interation of atoms and molecules. A large number of atoms `//` molecules `(` approximately `6.023xx10^(23))` are present in a few grams of any chemical compound varying with their atomic `//` molecular masses. To handle such large numbers conveniently, the mole concept was introduced. This concept has implications in diverse areas such as analytical chemistry, biochemistry, electrochemistry, and radiochemistry. The following example illustrates a typical case, involving chemical `//` electrochemical reaction, which requires a clear understanding of the mole concept. A `4.0M` aqueous solution of `NaCl` is prepared and `500mL` of this solution is electrolyzed. This leads to the evolution of chlorine gas at one of the electrodes `(` atomic mass of `Na ` is 23 and `Hg` is `200)(1F=96500C)`. The total charge `(` coulomb `)` required for complete electrolysis isA. 24125B. 48250C. 96500D. 193000 |
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Answer» Correct Answer - d `2Cl^(c-) rarr Cl_(2)+2e^(-)` Total charge `=2xx96500C` `=193000C` |
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| 1068. |
Which reference electrode is sued to measure the electrode potential of other electrodes? |
| Answer» Standard hydrogen electrode (SHE) whose electrode potential is taken as zero. | |
| 1069. |
When acidulated water (dil.H2SO4 solution) is electrolysed, will the pH of the solution be affected? Justify your answer. |
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Answer» pH of the solution will not be affected as [H+] remains constant. At anode : 2H2O → O2 + 4H+ + 4e– At cathode 4H+ + 4e– → 2H2 |
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| 1070. |
Chemical reactions involve interation of atoms and molecules. A large number of atoms `//` molecules `(` approximately `6.023xx10^(23))` are present in a few grams of any chemical compound varying with their atomic `//` molecular masses. To handle such large numbers conveniently, the mole concept was introduced. This concept has implications in diverse areas such as analytical chemistry, biochemistry, electrochemistry, and radiochemistry. The following example illustrates a typical case, involving chemical `//` electrochemical reaction, which requires a clear understanding of the mole concept. A `4.0M` aqueous solution of `NaCl` is prepared and `500mL` of this solution is electrolyzed. This leads to the evolution of chlorine gas at one of the electrodes `(` atomic mass of `Na ` is 23 and `Hg` is `200)(1F=96500C)`. If the cathode is an `Hg` electrode, the maximum weight `(in g)` of amalgam formed from this solution isA. 200B. 225C. 400D. 446 |
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Answer» Correct Answer - d `underset((2 mol))(Na+Hg)rarr underset((2 mol))(Na-Hg)` `2 mol` of amalgam `=23xx2+2xx200=446g` |
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| 1071. |
The calomel contain the ion isA. `Hg_(2)^(2+)`B. `Hg^(+)`C. `Hg^(2+)`D. `Hg_(2)^(+)` |
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Answer» Correct Answer - A `Hg_(2) Cl_(2) (s) hArr Hg_(2)^(2+) + 2 Cl^(-)` i.e., `Hg_(2)^(2+)` ions . |
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| 1072. |
(a). What is standard hydrogen electrode? (b). Give the reactions that occurs at this electrode wen it acts as positive in an electrochemical cell.A. anodeB. cathodeC. neither cathode nor anodeD. both anode and cathode |
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Answer» Correct Answer - A `E_(Zn^(2+) |Zn)^(@) lt E_(H^(+) | H)^(@)` |
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| 1073. |
Chemical reactions involve interation of atoms and molecules. A large number of atoms `//` molecules `(` approximately `6.023xx10^(23))` are present in a few grams of any chemical compound varying with their atomic `//` molecular masses. To handle such large numbers conveniently, the mole concept was introduced. This concept has implications in diverse areas such as analytical chemistry, biochemistry, electrochemistry, and radiochemistry. The following example illustrates a typical case, involving chemical `//` electrochemical reaction, which requires a clear understanding of the mole concept. A `4.0M` aqueous solution of `NaCl` is prepared and `500mL` of this solution is electrolyzed. This leads to the evolution of chlorine gas at one of the electrodes `(` atomic mass of `Na ` is 23 and `Hg` is `200)(1F=96500C)`. The total number of moles of chlorine gas evolved isA. `0.5`B. `1.0`C. `2.0`D. `3.0` |
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Answer» Correct Answer - b `4.0M NaCl, 500mL(0.5L)` moles of `NaCl=4xx0.5=2` 2 moles `NaCl-=2 ` moles `Cl^(c-)` `underset(2 mol)(2Cl^(c-))rarr underset(1 mol)(Cl_(2))` |
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| 1074. |
Tollen reagent is used for the detection of aldehydes. When a solution of `AgNO_(3)` is added to glucose with `NH_(4)OH`, then gluconic acid is formed. `Ag^(o+)+e^(-) rarr Ag," "E^(c-)._(red)=0.8V` `C_(6)H_(12)O_(6)rarr underset(Gluconic aci d)(C_(6)H_(12)O_(7)+)2H^(o+)+2e^(-) , " "E^(c-)._(o x i d ) =-0.05V` `[Ag(NH_(3))_(2)]^(o+)+e^(-) rarr Ag(s)+2NH_(3), " "E^(c-)._(red)=0.337V` `[Use2.303xx(RT)/(F)=0.0592` and `(F)/(RT)=38.92at 298 K ]` Ammonia is always added in this reaction. Which of the followijng must be wrong ?A. `NH_(3)` combines with `Ag^(o+)` to form a complex.B. `[Ag(NH_(3))_(2)]^(o+)` is a stronger oxidizing reagent than `Ag^(o+)`C. In the absence of `NH_(3)`, a silver salt of gluconic acid is formed.D. `NH_(3)` has affected the standard reduction potential of glucose `//` gluconic acid electrode. |
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Answer» Correct Answer - d Ammonia has no effect on the standard reduction potential. |
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| 1075. |
Which one of the following statements is wrong ?A. The electrode potential is called standard electrode potential if the electrode is set up in 1 M solution at 298 KB. The electrode potential of Pt `H_(2 "(1 atm)") | H^(+) (1M)` is taken as zeroC. Metals which have higher standard electrode potential than N.H.E. react with 1 M `H_(2)SO_(4)` to give `H_(2) ` gasD. Greater the oxidation potential of a metal , more active is the metal . |
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Answer» Correct Answer - C Metals with higher oxidation potential (lower reduction potentials) react with acids to give `H_(2)` gas . |
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| 1076. |
Which one of the following statements is incorrect ?A. The tendency of an electrode to lose electrons with respect to Normal Hydrogen Electrode is called its oxidation potential .B. The standard oxidation potentials are taken as positive whereas standard reduction potentials are taken as negative .C. Oxidation potential and reduction potential of an electrode are equal in magnitude .D. The absolute value of the electrode potential cannot be determined . |
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Answer» Correct Answer - B Standard reduction potentials are taken as positive . |
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| 1077. |
Tollen reagent is used for the detection of aldehydes. When a solution of `AgNO_(3)` is added to glucose with `NH_(4)OH`, then gluconic acid is formed. `Ag^(o+)+e^(-) rarr Ag," "E^(c-)._(red)=0.8V` `C_(6)H_(12)O_(6)rarr underset(Gluconic aci d)(C_(6)H_(12)O_(7)+)2H^(o+)+2e^(-) , " "E^(c-)._(o x i d ) =-0.05V` `[Ag(NH_(3))_(2)]^(o+)+e^(-) rarr Ag(s)+2NH_(3), " "E^(c-)._(red)=0.337V` `[Use2.303xx(RT)/(F)=0.0592` and `(F)/(RT)=38.92at 298 K ]` `2Ag^(o+)+C_(6)H^(12)O_(6)+H_(2)O rarr 2Ag^(s)+C_(6)H_(12)O_(7)+2H^(o+)` Find `lnK` of this reaction.A. `66.13`B. `58.38`C. `28.30`D. `46.29` |
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Answer» Correct Answer - b Cell reaction `:` `i. Ag^(o+)+e^(-) rarr Ag(s)," "E^(c-)._(red)=0.8V` `ii. C_(6)H_(12)O_(6)rarr C_(6)H_(12)O_(7)+2H^(o+)+2e^(-), " "E_(o x i d)=-0.05V` Hence, for reaction `2Ag^(o+)+C_(6)H_(12)O_(6)+H_(2)Orarr 2Ag(s)+C_(6)H_(12)O_(7)+2H^(o+)` `E^(c-)._(cell)=0.8-0.05` `=0.75V` `E_(cell)=E^(c-)._(cell)-(2.303)/(nF)log K` At equilibrium, `E_(cell)=0` `:. E^(c-)._(cell)=(2.303RT)/(nF)log K` `0.75=(0.0592)/(2) log K` `log K =(2xx0.75)/(0.0592)=25.33` or `ln K =2.303xxlogk` `=2.303xx25.33` `=58.35` |
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| 1078. |
The cell potential (E) and the free energy change `(Delta G)` accompanying an electrochemical reaction are related byA. `Delta G = n F "log" E`B. `Delta G = n FE`C. `-Delta G = n FE`D. `- Delta G = n F " log" E` |
| Answer» Correct Answer - C | |
| 1079. |
At anode in the electrolysis of fused `NaCI`:A. `Na^(+)` is oxidisedB. `Cl^(-)` is oxidisedC. Cl is reducedD. Na is reduced |
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Answer» Correct Answer - B At anode, in the electrolysis of fused `NaCl,Cl^(-)` is oxidsied to `Cl_(2)`. |
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| 1080. |
The cell voltage is independent of the size of the cell or electrodes. |
| Answer» Correct Answer - T | |
| 1081. |
The chemical change in an electrolytic cell is non`-` spontaneous. |
| Answer» Correct Answer - T | |
| 1082. |
The oxide which can be reduced by hydrogen is :A. `Na_(2)O`B. `CaO`C. `K_(2)O`D. `CuO` |
| Answer» Correct Answer - D | |
| 1083. |
By how much is the oxidizing power of `Cr_2O_7^(2-)"|"Cr^(3+)` couple decreased if the `H^+` concentration is decreased from 1M to `10^(-30`M at `25^(@)` C?A. 0.001 VB. 0.207 VC. 0.441 VD. 0.414 V |
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Answer» Correct Answer - D |
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| 1084. |
The reference calomel electrode is made from which of the following ?A. `ZnCl_(2)`B. `CuSO_(4)`C. `HgCl_(2)`D. `Hg_(2)Cl_(2)`. |
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Answer» Correct Answer - D Calomel electrode used as a reference electrode uses `Hg_(2)Cl_(2)`. |
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| 1085. |
The electrode potential of calomel electrode , used as a reference electrodeA. is taken as zero alwaysB. is a taken as zero if concentration of KCl solution is 1 MC. can be zero , negative or positiveD. depends upon the concentration of KCl solution used . |
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Answer» Correct Answer - D The electrode potential of calomel electrode depends upon the concentration of KCl solution . |
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| 1086. |
The reference calomel electrode is made from which of the following ?A. `ZnCl_(2)`B. `CuSO_(4)`C. `Hg_(2)Cl_(2)`D. `HgCl_(2)` |
| Answer» Correct Answer - C | |
| 1087. |
The units of conducivity are :A. `"siemens"^(-1) cm^(-1)`B. siemens cmC. siemens `cm^(-1)`D. siemens `cm^(-2) mol^(-1)` |
| Answer» Correct Answer - C | |
| 1088. |
A chemical reaction will be non-spontaneous ifA. `E_("cell")^(@)` is positiveB. `DeltaG^(@)` is negativeC. reaction quotient, `Q lt K`D. `E_("cell")` is negative |
| Answer» Correct Answer - D | |
| 1089. |
Which of the following is thecorrect order in which metals displace each other from the salt solution of their salts?A. Zn,Al,Mg,Fe,CuB. Cu,Fe,Mg,Al,ZnC. Mg,Al,Zn,Fe,CuD. Al,Mg,Fe,Cu,Zn |
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Answer» Correct Answer - C In reactivity series , Mg gt Al gt Zn gt Fe gt Cu `overset"Reactivity decreases"to ` Hence, Mg can displace Al, Al can displace Zn and so on. |
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| 1090. |
Which has the highest oxidizing power?A. `I_(2)`B. `Br_(2)`C. `F_(2)`D. `Cl_(2)` |
| Answer» Correct Answer - C | |
| 1091. |
A cell is set up as shown in the figure. It is observed that EMF of the cell comes out to be 2.36 V. Which of the given statements is not correct about the cell? A. Reduction takes place at magnesium electrode and oxidation at SHE.B. Oxidation takes place at magnesium electrode and reduction at SHE.C. Standard electrode potential for `Mg^(2+)//Mg` will be-2.36 V.D. Electrons flow from magnesium electrode to hydrogen electrode. |
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Answer» Correct Answer - A oxidation takes place at magnesium electrode and reduction at hydrogen electrode |
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| 1092. |
Match the List-I with List-II `{:(,"List-I (Electrode)",,"List -II (Type)"),(1,"Calomel",(A),"Reference"),(2,"Glass",(B),"Redox"),(3,"Hydrogen",(C),"Membrane"),(4,"Quinhydrone",(D),"Gas"),(,,,):}`A. `1-A, 2-C, 3-D, 4-B`B. `1-B, 2-A, 3-D, 4-C`C. `1-C, 2-B, 30A, 4-D`D. `1 - D, 2-A, 3-C, 4-B` |
| Answer» Correct Answer - A | |
| 1093. |
A standard hydrogen electrode has zero electrode potential is assumed to beA. negativeB. zeroC. positiveD. fractional |
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Answer» Correct Answer - B `E^(@)` for SHE has been assumed to be zero. |
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| 1094. |
A standard hydrogen electrode has zero electrode potential because :A. hydrogen is easiest to oxidiseB. the electrode potential is assumed to be zeroC. hydrogen atom has only one electronD. hydrogen is the lightest element |
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Answer» Correct Answer - B (b) Conceptual question. |
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| 1095. |
A standard hydrogen electrode has zero electrode potential because :A. hydrogen is easier to oxidiseB. this electrode potential is assumed to be zeroC. hydrogen atom h as only on e electronD. hydrogen is the lightest element. |
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Answer» Correct Answer - B The value is arbitrary. |
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| 1096. |
A standard hydrogen electrode has zero electrode potential because :A. hydrogen can be most easily oxidisedB. hydrogen has only one electronC. the electrode potential is assumed to be zeroD. hydrogen is the lightest element. |
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Answer» Correct Answer - C According to convention, the standard hydrogen electrode is assigned a zero potential at all temperature |
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| 1097. |
The potential of a single electrode depends uponA. nature of metalB. concentration of metal ions is solutionsC. temperatureD. all. |
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Answer» Correct Answer - D Electrode potential of half-cell depends on (a) , (b) and (c) . |
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| 1098. |
Electrode potential of any electrode depends are:A. nature of the metalB. temperature of the solutionsC. molarity of the solutionD. all of these |
| Answer» Correct Answer - D | |
| 1099. |
Copper from copper sulphate solution can be displaced by …………. The standard reducation potentials of some electrodes are given below: (a) `E^(@) (Fe^(2+), Fe) = -0.44 V` (b) `E^(@) (Zn^(2+), Zn) = -0.76 V` (c) `E^(@) (Cu^(2+), Cu) = +0.34 V` (d) `E^(@) (H^(+), 1//2H_(2)) = +0.34 V`A. `H^(2)`B. `Zn`C. `Cr`D. `Fe` |
| Answer» All have more `E_(OP)^(@)` values than `E_(O_(Cu))` | |
| 1100. |
The electrode potential of a SHE depends uponA. concentration of chloride ionsB. concentration of hydrogen ionsC. concentration of KCl solutionD. concentration of `H_(2)SO_(4)` |
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Answer» Correct Answer - B The electrode potential of gas electrode depends on `[H^(+)]` and pressure at gas . |
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