Quiz about ELECTROCHEMISTY IN GENERAL AWARENESS

Question 1

The EMF of the following cell `Zn| Zn^(2+)(0.1M) || Cl^(-)(0.01M) | AgCl | Ag` is [Given E_(Zn^(2+)|Zn)^(@) = -0.76V` `E_(Cl^(-)| AgCl|Ag)^(@)` = 0.22 V` `(2.303RT)(F) = 0.06]`A. 0.96 VB. 0.345 VC. 1.23D. 1.13 V

Accepted Answer

NA

Question 2

`DeltaG^(@)` of the cell reaction `AgCl(s) + 12H_(2) rightarrow Ag(s) + H^(+) + Cl^(-)` is `-21.52kJ`. `DeltaG^(@)` of 2AgCl(s) + H_(2)(g) rightarrow + 2H^(+) + 2Cl^(-)` isA. `-21.52kJ`B. `-10.76 kJ`C. `-43.04kJ`D. `43.04 kJ`

Accepted Answer

NA

Question 3

The emf of the cell `Zn|ZnCl_(2)` (0.05M) | AgCl(s)`Ag is 1.015 V at 298 K and the temperature coefficient of its emf is `-4.92 xx 10^(-4)` VK. How many of the reaction thermodynamic parameter `DeltaG` `DeltaS` and `DeltaH` are negative at 298 K?A. None of themB. One of themC. Two of themD. All of them

Accepted Answer

NA

Question 4

The Gibbs energy for the decomposition of `Al_(2)O_(3)` at `500^(@)C` is as follow  `(2)(3)Al_(2)O_(3) rarr (4)(3)Al+O_(2) Delta_(r)G= +960 kJ mol^(-1)` The potential difference needed for the electrolytic reduction of aluminium oxide `(Al_(2)O_(3))` at `500^(@)C` isA. 4.5 VB. 3.0 VC. 2.5 VD. 5.0 V

Accepted Answer

NA

Question 5

Based on the data given below the correcy order of reducing power is `Fe_((aq.))^(3+) + e rarr Fe_((aq.))^(2+) E^(@) = +0.77 V` `Al_((aq.))^(3+) + 3e rarr Al_((s)) E^(@) = -1.66 V` `Br_(2(aq.)) + 2e rarr 2Br_((aq.))^(-) E^(@) = +1.08 V`A. `Br^(-) lt Fe(2+) lt Al`B. `Fe^(2+) lt Al lt Br^(-)`C. `Al lt Br^(-) lt Fe^(2+)`D. `Al lt Fe^(2+) lt Br^(-)`

Accepted Answer

NA

Question 6

For the electrolytic production of `NaClO_(4)` from `NaClO_(3)` as per the following equation `NaClO_(3) + H_(2)O rightarrow NaClO_(4) + H_(2)` How many faradays of electricity will be required to produce 0.5 mole of `NaClO_(4)` assuming 60% efficiency?A. 0.835 FB. 1.67 FC. 3.34 FD. 1.6 F

Accepted Answer

NA

Question 7

What must be concentration of `Ag^(+)` in an aqueous solution containing `Cu^(2+) =1.0 M` so that bot the metals can be deposited on the cathode simultaneously. Given that `E_(CuCu^(2+))^(0)=-0.34V` and `E_(Ag^(+)Ag)^(0)=0.812VT=298K`A. Nearly `10^(-19)` MB. `10^(-12)` MC. `10^(-8)` MD. Nearly `10^(-16)` M

Accepted Answer

NA

Question 8

Which process occurs in the electrolysis of an aqueous tin (II) chloride solution at a tin anode?A. Sn = `Sn^(2+) + 2e^(-)`B. `2Cl^(-) = Cl_(2) + 2e^(-)`C. `2H_(2)O = O_(2) + 4H^(+) + 4e^(-)`D. None of these

Accepted Answer

NA

Question 9

How many electrons flow when a current of 5 amperes is passed through a conductor for 200 seconds?A. `6.241 xx 10^(21)`B. `6.0241 xx 10^(21)`C. `6.241 xx 10^(22)`D. `6.0241 xx 10^(20)`

Accepted Answer

NA

Question 10

The number of electrons delivered at the cathode during electrolysis by a current of `1` ampere in 60 seconds is (charger on electron `= 1.60 xx 10^(-19)C`)A. `3.74 xx 10^(20)`B. `6.0 xx 10^(23)`C. `7.48 xx 10^(21)`D. `6.0 xx 10^(20)`

Accepted Answer

NA

Question 11

During discharge of a lead storage cell the density of sulphuric acid in the cellA. increasesB. decreasesC. remains unchangedD. initially increases but decreases subsequently

Accepted Answer

NA

Question 12

Rechargable batteries include which of the those below? (P) Dry cell (Q) Lead-acid storage battery (R ) Nickel -cadmium batteryA. Q onlyB. P and Q onlyC. Q and R onlyD. PQ and R only

Accepted Answer

NA

Question 13

The potential of the Daniel cell `Zn |(ZnSO_(4))||(CuSO_(4)|Cu` was reported by Buckbee Surdzial and Metz as `E^(@) = 1.1028 - 0.641 xx 10^(-3)T` + `0.72 xx 10^(-5)T^(2)` where T is the temperature in degree celcius Calcualte `DeltaS^(@0` for the cell reaction at `25^(@)C`.A. `-45.32 EU`B. `-34.53 EU`C. `-25.43 EU`D. `54.23 EU`

Accepted Answer

NA

Question 14

At 298 K the standard free energy of formation of `H_(2)O(l)` is `-237.20 kJmole` while that of its ionisation into `H^(+)` ions and hydroxyl ions is `80kJmole` then the emf of the following cell at 298 K will be  [Take 1F = 96500 C] `H_(2)O(g 1 bar)|H^(+)(1M)||OH^(-)(1M) |O_92)(g 1bar)`A. 0.40 VB. 0.81 VC. 1.23 VD. `-0.40 V`

Accepted Answer

NA

Question 15

What is cell entropy change of the following cell? `Pt(s)|H_(2)(g)|CH_(3)COOH HCl||KCl(aq) |Hg_(2)Cl_(2)(s)|Hg` P = 1atm 0.1 M 0.1M EMF of the cell is found to be `0.045 v at 298 K and temperature coefficient is `34 xx 10^(-4)VK^(-1)` Given `K_(a(CH_(3)COOH)) = 10^(-5) M`A. 60B. 65.6C. 69.2D. 63.5

Accepted Answer

NA

Question 16

A 3.00amp current is used to electrolyze the molten chlorides `CaCl_(2)MgCl_(2)AlCl_(3)` and `FeCl_(3)`. The deposition of which mass of metal will require the longest electrolysis time?A. 100g CaB. 50g MgC. 75g AlD. 125g Fe

Accepted Answer

NA

Question 17

Given below are a set of half-cell reactions (acidic medium) along with their `E_(@)` with respect to normal hydrogen electrode values. Using the data obtain the correct explanation to question given below. `(I_(2)+2e^(-)rarr2I^(-)E^(@)=0.54)(Cl_(2)+2e^(-)rarr2Cl^(-)E^(@)=1.36)(Mn^(2+)+e^(-)rarrMn^(2+)E^(@)=1.50)(Fe^(3+)+e^(-)rarrFe^(2+)E^(@)=0.77)(O_(2)+4H^(+)+4e^(-)rarr2H_(2)OE^(@)=1.23)` While `Fe^(2+)` is stable `Mn^(3+)` is not stable in acid solution becauseA. `O_(2)` oxidises `Mn^(2+)` to `Mn^(3+)` and `Fe^(2+)` to `Fe^(3+)`B. `O_(2)` oxidises both `Mn^(2+)` to `Mn^(3+)` and `Fe^(2+)` to `Fe^(3+)`C. `Fe^(3+)` oxidises `H_(2)O` to `O_(2)`D. `Mn^(3+)` oxidises `H_(2)O` to `O_(2)`

Accepted Answer

NA

Question 18

Statement-1 Absolute value of `E_(red)^(@)` of an electrode cannot be determined. statement-2 Neither oxidation nor reduction can take place alone.A. Statement-1 is True Statement-2 is True Statement-2 is a correct explanation for Statement-2B. Statement-1 is True Statement-2 is True Statement-2 is `NOT` a correct explanation for Statement-2C. Statement-1 is True Statement-2 is False.D. Statement-1 is False Statement-2 is True.

Accepted Answer

NA

Question 19

Pure water is saturated with pure solid AgCl a silver electrode is placed in the solution and the potential is measured agains normal calomet electrode at `25^(@)C`. This experiment is then repeated with a saturated solution of AgI. If the difference in potential in the two cases is 0.177V. What is the ratio of solubility product (solubility) of AgCl and AgI at the temperature of the experiment?A. `10^(3)`B. `10^(6)`C. `10^(2)`D. `10^(4)`

Accepted Answer

NA

Question 20

Statement-1 The electrode potential of SHE is zero only at `25^(@)C` and not at any other temperature. Statement-2 SHE is standard reference electrode.A. Statement-1 is True Statement-2 is True Statement-2 is a correct explanation for Statement-1B. Statement-1 is True Statement-2 is True Statement-2 is `NOT` a correct explanation for Statement-1C. Statement-1 is True Statement-2 is False.D. Statement-1 is False Statement-2 is True.

Accepted Answer

NA

Question 21

When connected to a Standard Hydrogen Electrode (SHE) electrons flow from an unknown half cell to the SHE. Which statement is correct?A. The unknown half cell is the anode.B. Oxidation occurs at the SHE.C. `E_(red)^(@)` for the unknown half cell is positive.D. `E_(cell)^(@)` is negative.

Accepted Answer

NA

Question 22

Given these standards reduction potentials what is the free energy change (in kJ. Mol^(-) for the reaction `Pb(s) + 2Ag^(+)(aq) rightarrow Pb^(2+)(aq) + 2Ag(s)` `Ag^(+)(aq) + e^(-) rightarrow Ag(s)` `E^(@) = 0.80V` `Pb^(2+)(aq) + 2e^(-) rightarrow Pb(s)` `E^(@) = -0.13V`A. -180B. -90C. 90D. 180

Accepted Answer

NA

Question 23

`2Ag^(+)(aq) + Cu(s) rightarrow Cu^(2+)(aq) + 2Ag(s)` The standard potential for this reaction is 0.46 V. Which change will increase the potential the most?A. Doubling the `[Ag^(+)]`B. Halving the `[Cu^(2+)]`C. Doubling the size of the Cu(s) electrode.D. Decreasing the size of the Ag electrode by one half.

Accepted Answer

NA

Question 24

Given these standard reduction potentials what is the standard reduction potential for `Co^(3+)(aq) + 3e^(-) rightarrow Co(s)`? `Co^(3+)(aq) + e^(-) rightarrow Co^(2+)(aq) E^(@) = 1.82V` `Co^(2+)(aq) + 2e^(-) rightarrow Co(s) E^(@) = -0.28V`A. 2.10VB. 1.54vC. 1.26vD. 0.42V

Accepted Answer

NA

Question 25

The equilibrium `Cu^(++)` (aq) + Cu(s) rightarrow 2Cu^(+)` established at `20^(@)`C corresponds to `[Cu^(++)][Cu^(+)]^(2) = 2.02 x x10^(4)`. The standard potential `E_(Cu^(++)Cu)^(@) = 0.33` volt. At this temperature what is the standard potential `E_(CuCu)^(@)`?A. `-0.457V`B. `1.54V`C. `1.26V`D. `0.42V

Accepted Answer

NA

Question 26

The molar conductance of NaCl varies with the concentration as shown in the following table and all values follows the equation. `lambda_(m)^(c)=lambda_(m)^(oo)-bsqrt(C)` where `lambda_(m)^(c)`= molar specific conductance `lambda_(m)^(oo)=` molar specific conductance at infinite dilution C=molar concentration  When a certain conductivity cell (C) was filled with 25`xx10^(-4)(M) NaCl` solution the resistance of the cell was found to be 1000 ohm. At infinite dilution conductance of `Cl^(-)` and `SO_(4)^(2-)` are `80ohm^(-1) cm^(2) mole^(-1)` and `160ohm^(-1) cm^(2) mole^(-1)` respectively. What is the cell constant of the conductivity cell (C)?A. `0.385 cm^(-1)`B. `3.85cm^(-1)`C. `38.5cm^(-1)`D. `0.1925cm^(-1)`

Accepted Answer

NA

Question 27

The molar conductance of NaCl varies with the concentration as shown in the following table and all values follows the equation. `lambda_(m)^(c)=lambda_(m)^(oo)-bsqrt(C)` where `lambda_(m)^(c)`= molar specific conductance `lambda_(m)^(oo)=` molar specific conductance at infinite dilution C=molar concentration  When a certain conductivity cell (C) was filled with 25`xx10^(-4)(M) NaCl` solution the resistance of the cell was found to be 1000 ohm. At infinite dilution conductance of `Cl^(-)` and `SO_(4)^(2-)` are `80ohm^(-1) cm^(2) mole^(-1)` and `160ohm^(-1) cm^(2) mole^(-1)` respectively. What is the molar conductance of NaCl at infinite dilution?A. `147 ohm^(-1) cm^(2) mole^(-1)`B. `107ohm^(-1) cm^(2) mole^(-1)`C. `127 ohm^(-1) cm^(2) mole^(-1)`D. `157ohm^(-1) cm^(2) mole^(-1)`

Accepted Answer

NA

Question 28

The equivalent conductivity of KCl at inifinite dilution is 130 S `cm^(2) eq^(-1)`. The transport number of `Cl^(-)` ion in KCl at the same temperature is 0.505. The limiting ionic mobility of `K^(+)` ion isA. `6.67xx10^(-4) sec^(-1)volt^(-1)`B. `5.01xx10^(-3)cm^(2)sec^(-1)volt^(-1)`C. `3.22xx10^(-4)cm^(2)sec^(-1)volt^(-1)`D. `2.00xx10^(-4)cm^(2)sec^(-1) volt^(-1)`

Accepted Answer

NA

Question 29

Acetic acid is titrated with NaOH solution. Which of the following statement is correct for this titration?A. Conductance increases upto equivalence point then it decreaseB. Conductance increases upto equivalnce point then it increases.C. First conductance increases slowly upto equivalence point and then increases rapidly.D. First conductane increases slowly upto equivalence point and then drops rapidly

Accepted Answer

NA

Question 30

The molar conductance of NaCl vauies with the concentration as shown in the following table. And all values follows the equation `lambda_(m)^(C)=lambda_(m)^(oo)-bsqrtC` Where `lambda_(m)^(C)`= molar specific conductance `lambda_(m)^(oo)`=molar specific conductance at infinite dilution C = molar concentration `(Molar concentrationMolar conductance of NaCl in ohm^(-1)cm^(2)mole^(-1))(4xx10^(-4)107)(9xx10^(-4)97)(16xx10^(-4)87)` When a certain conductivity cell (C) was filled with `25xx10^(-4)(M)` NaCl solution. The resistance of the cell was found to be 1000 ohm. At Infinite dilution conductance of `CI^(-)` and `SO_(4)^(-2)` are 80 `ohm^(-1)cm^(2)mole^(-1)` and 160 `ohm^(-1)cm^(2)mole^(-1)` respectively. It the cell (C) is filled with `5xx10^(-3)(N)Na_(2)SO_(4)` the obserbed resistance was 400 ohm. What is the molar conductance of `Na_(2)SO_(4)`.A. `19.25 ohm^(-!)cm^(2)mole^(-1)`B. `96.25 ohm^(-1)cm^(2)mole^(-1)`C. `385 ohm^(-1) cm^(2) mole^(-1)`D. `192.5 ohm^(-1)cm^(2) mole^(-1)`

Accepted Answer

NA

Question 31

A fuel cell is a cell that is continuously supplied with an oxidant and a reductant so that it can deliver a current indefinitely. Fuel cell offer the possibility of achieving high thermodynamic efficiency in the conversion of Gibbs energy into mechanical work. Internal combustion engines at best convert only the fraction `(T_(2)-T_(1))T_(2)` of heat of combustion into mechanical work. While the thermodynamic efficiency of the fuel cell is give by `eta=(|DeltaG|)(|DeltaH|)` where `DeltaG` is the Gibbs energy change for the cell reaction and `DeltaH` is the enthalpy change of the cell reaction. This efficiency can be upto 80%-90% also in contrast to normal heat engine efficiency which are generally about 40%  Fuel cells may be classified according to the temperature range in wich they operate low temperature (25 to `100^(@)C`) medium temperature (100 to `500^(@)C)`) high temperature `(500 to 1000^(@)C)` and very high temperature is that catalyst for the various steps in the process are not so necessary. Polarization of a fuel cell reduces the current. Polarization is the result of slow reactions or processes such as diffusion in the cell. The figure indicates the construction of hydrogen-oxygen fuel cell with a solid electrolyte which is an ion exchange membrane. The membrane is impermeable to the reactant gases but is permeable to hydrogen ions which carry the current between the electrodes. To facillitate the operation finely divided platinum that function as a catalyst. Water is drained out of the cell during operation. Fuel cells of this general type have been used successfully in the space program and are quite efficient. their disadvantages for large-scale commercial application are that hydrogen presetns storage problems and platinum is an expensive catalyst. Cheaper catalysts have been found for higher temperature operatureof hydrogen-oxygen fuel cells. Fuel cells taht use hydrocarbons and air have been developed but their power per unit weight is too low to make them practical in ordinary automobiles. Better catalysts are needed. A hydrogen-oxygen fuel cell may hae an acidic or alkaline electrolyte. The half-cell reactions are `(1)(2)O_(2)(g)+2H^(+)+2e^(-)rarrH_(2)O(l) E^(@)=1.2288V` `2H^(+)+2e^(-)rarrH_(2)(g)E^(@)=0` `H_(2)(g)+(1)(2)O_(2)(g)rarrH_(2)O(l) E^(@)=1.2288V` or `(1)(2)O_(2)(g)+H_(2)O(g)+2e^(-)rarr2OH^(-) E^(@)=0.4009V` `2H_(2)O(l)+2e^(-)rarrH_(2)(g)+2OH^(-)E^(@)=-0.8279V` `H_(2)(g)+(1)(2)O_(2)(g)rarrH_(2)O(l) E^(@)=1.2288V` To maximize the power per unit mass of an electrochemical cell the electronic and electrolytic resistances of the cell must be minimized. than aqueous solutions high-temperature electrochemical cells are of special interest for practical applications. High temperature also allow the use of liquid metal electrode which makes possibel high current densities than solid electrodes. For a hydrogen-oxygen fuel cell if `DeltaH_(f)^(2)(H_(2)Ol)=-285kJmole` then what will be its thermodynamic efficiency under standard conditions (use data given in the passage if required)?A. 0.91B. 0.41C. 0.63D. 0.83

Accepted Answer

NA

Question 32

A fuel cell is a cell that is continuously supplied with an oxidant and a reductant so that it can deliver a current indefinitely. Fuel cell offer the possibility of achieving high thermodynamic efficiency in the conversion of Gibbs energy into mechanical work. Internal combustion engines at best convert only the fraction `(T_(2)-T_(1))T_(2)` of heat of combustion into mechanical work. While the thermodynamic efficiency of the fuel cell is give by `eta=(|DeltaG|)(|DeltaH|)` where `DeltaG` is the Gibbs energy change for the cell reaction and `DeltaH` is the enthalpy change of the cell reaction. This efficiency can be upto 80%-90% also in contrast to normal heat engine efficiency which are generally about 40%  Fuel cells may be classified according to the temperature range in wich they operate low temperature (25 to `100^(@)C`) medium temperature (100 to `500^(@)C)`) high temperature `(500 to 1000^(@)C)` and very high temperature is that catalyst for the various steps in the process are not so necessary. Polarization of a fuel cell reduces the current. Polarization is the result of slow reactions or processes such as diffusion in the cell. The figure indicates the construction of hydrogen-oxygen fuel cell with a solid electrolyte which is an ion exchange membrane. The membrane is impermeable to the reactant gases but is permeable to hydrogen ions which carry the current between the electrodes. To facillitate the operation finely divided platinum that function as a catalyst. Water is drained out of the cell during operation. Fuel cells of this general type have been used successfully in the space program and are quite efficient. their disadvantages for large-scale commercial application are that hydrogen presetns storage problems and platinum is an expensive catalyst. Cheaper catalysts have been found for higher temperature operatureof hydrogen-oxygen fuel cells. Fuel cells taht use hydrocarbons and air have been developed but their power per unit weight is too low to make them practical in ordinary automobiles. Better catalysts are needed. A hydrogen-oxygen fuel cell may hae an acidic or alkaline electrolyte. The half-cell reactions are `(1)(2)O_(2)(g)+2H^(+)+2e^(-)rarrH_(2)O(l) E^(@)=1.2288V` `2H^(+)+2e^(-)rarrH_(2)(g)E^(@)=0` `H_(2)(g)+(1)(2)O_(2)(g)rarrH_(2)O(l) E^(@)=1.2288V` or `(1)(2)O_(2)(g)+H_(2)O(g)+2e^(-)rarr2OH^(-) E^(@)=0.4009V` `2H_(2)O(l)+2e^(-)rarrH_(2)(g)+2OH^(-)E^(@)=-0.8279V` `H_(2)(g)+(1)(2)O_(2)(g)rarrH_(2)O(l) E^(@)=1.2288V` To maximize the power per unit mass of an electrochemical cell the electronic and electrolytic resistances of the cell must be minimized. than aqueous solutions high-temperature electrochemical cells are of special interest for practical applications. High temperature also allow the use of liquid metal electrode which makes possibel high current densities than solid electrodes. If 567.5 mL of `H_(2)` gas at STP is fed into and is consumed by the cell in 10minutes then what is the current output (in A) of the fuel cell?A. 4AB. 8AC. 16AD. 12A

Accepted Answer

NA

Question 33

A fuel cell is a cell that is continuously supplied with an oxidant and a reductant so that it can deliver a current indefinitely. Fuel cell offer the possibility of achieving high thermodynamic efficiency in the conversion of Gibbs energy into mechanical work. Internal combustion engines at best convert only the fraction `(T_(2)-T_(1))T_(2)` of heat of combustion into mechanical work. While the thermodynamic efficiency of the fuel cell is give by `eta=(|DeltaG|)(|DeltaH|)` where `DeltaG` is the Gibbs energy change for the cell reaction and `DeltaH` is the enthalpy change of the cell reaction. This efficiency can be upto 80%-90% also in contrast to normal heat engine efficiency which are generally about 40%  Fuel cells may be classified according to the temperature range in wich they operate low temperature (25 to `100^(@)C`) medium temperature (100 to `500^(@)C)`) high temperature `(500 to 1000^(@)C)` and very high temperature is that catalyst for the various steps in the process are not so necessary. Polarization of a fuel cell reduces the current. Polarization is the result of slow reactions or processes such as diffusion in the cell. The figure indicates the construction of hydrogen-oxygen fuel cell with a solid electrolyte which is an ion exchange membrane. The membrane is impermeable to the reactant gases but is permeable to hydrogen ions which carry the current between the electrodes. To facillitate the operation finely divided platinum that function as a catalyst. Water is drained out of the cell during operation. Fuel cells of this general type have been used successfully in the space program and are quite efficient. their disadvantages for large-scale commercial application are that hydrogen presetns storage problems and platinum is an expensive catalyst. Cheaper catalysts have been found for higher temperature operatureof hydrogen-oxygen fuel cells. Fuel cells taht use hydrocarbons and air have been developed but their power per unit weight is too low to make them practical in ordinary automobiles. Better catalysts are needed. A hydrogen-oxygen fuel cell may hae an acidic or alkaline electrolyte. The half-cell reactions are `(1)(2)O_(2)(g)+2H^(+)+2e^(-)rarrH_(2)O(l) E^(@)=1.2288V` `2H^(+)+2e^(-)rarrH_(2)(g)E^(@)=0` `H_(2)(g)+(1)(2)O_(2)(g)rarrH_(2)O(l) E^(@)=1.2288V` or `(1)(2)O_(2)(g)+H_(2)O(g)+2e^(-)rarr2OH^(-) E^(@)=0.4009V` `2H_(2)O(l)+2e^(-)rarrH_(2)(g)+2OH^(-)E^(@)=-0.8279V` `H_(2)(g)+(1)(2)O_(2)(g)rarrH_(2)O(l) E^(@)=1.2288V` To maximize the power per unit mass of an electrochemical cell the electronic and electrolytic resistances of the cell must be minimized. than aqueous solutions high-temperature electrochemical cells are of special interest for practical applications. High temperature also allow the use of liquid metal electrode which makes possibel high current densities than solid electrodes. Why are fuel cells not being used in daily life depite their very high efficiency?A. The fuels needed for their operation are rarely found in nature.B. Their operation always needs very high temperature and do not work at low temperature.C. The catalyst used in fuel cells at normal temperature are very expensiveD. The design of fuel cells is so complicated that it is not feasible to construct these for daily life applications.

Accepted Answer

NA

Question 34

By the electrolysis of aqueous solution of `CuSO_(4)` the products obtained at both the inert electrodess areA. `O_(2)` at anode and `H_(2)` at cathode.B. `H_(2)` at anode and Cu at cathodeC. `O_(2)` at anode and Cu at cathodeD. `H_(2)S_(2)O_(8)` at anode and `O_(2)` cathode.

Accepted Answer

NA

Question 35

During the electrolysis of aqueous zinc nitrate.A. Zn plates out at the cathodeB. Zn plats out at the anodeC. `H_(2)` gas is evolved at the anodeD. `O_(2)` gas is evolved at the anode.

Accepted Answer

NA

Question 36

Which of the following are correct in acidic medium?A. The oxidising power of `KMnO_(4)` will increase with increase in pHB. The oxidising power of `KMnO_(4)` will decrease with increase in pHC. The oxidising of `K_(2)Cr_(2)O^(7)` will increase with increase in pHD. The oxidising power of `K_(2)Cr_(2)O^(7)` will decrease with increase in pH

Accepted Answer

NA

Question 37

Which of the following statement(s) isare correct?A. The equilibrium constant of cell reaction in a concentration cell is 1B. Activity of a radioactive nucleus is temperature independent.C. Limiting molar conductivities `(A_(m)^(-))` of NaCl and KCl are different due to difference in ionic mobilities of `Na^(+)` (aq) and `K^(+)` (aq) ions.D. When aq. Solution of 2Mj-HCl is electrolysed more `H^(+)` ions are reduced at cathode than `Cl^(-)` ions at anode due to higher ionic mobility of `H^(+)` (aq) ions.

Accepted Answer

NA

Question 38

Choose the correct statement(s)A. Cell constant values of conductivity cells are independent of the solution filled into the cell.B. Kohlrausch law is valid for strong eletrolyte but not for weak electrolyte.C. In general conductivity decreases on dilution whereas equivalent and molar conductivity increase on dilution.D. Salt bridge is employed to maintain the electrical neutrality and to minimize the liquid -liquid junction potential.

Accepted Answer

NA

Question 39

Electrode potential data are used for predicting fessibility of any process. These are particularly useful in deciding products obtained on electrolysis and also on suitability of any substance for quantitative estimation. Some of the electrode potentials are given below  An aqueous solution is taken comprising of `Fe^(+3)Mn^(+2)Fe^(+2)C_(2)O_(4)^(2-)` and `Cl^(-)` all at standard conditions. The solution is subjected to electrolysis using inert electrodes ensuring that pH of the solution remains as 7. Identify the option which is correct regarding products obtained [assume that except `[H^(+)]` all other species involved are present at standard conditions].A. At cathode Mn will be deposited initiallyB. At cathode `H_(2)(g)` will be dposited initiallyC. At cathode `Cl_(2)(g)` will be deposited initiallyD. None of the above statements are correct

Accepted Answer

NA

Question 40

Electrode potential data are used for predicting fessibility of any process. These are particularly useful in deciding products obtained on electrolysis and also on suitability of any substance for quantitative estimation. Some of the electrode potentials are given below  On adding `KMnO_(4)` solution to an aqueous solution of ferrous oxalate in presence of `HCl` it is observed that 0.1 mole of `Cl_(2)(g)` and 0.2 moles of `CO_(2)(g)` was obtained. What must be the amount of `KMnO_(4)` compound taken?A. 0.1molesB. `(0.4)(5)` molesC. `(0.3)(5)` molesD. 0.5 moles

Accepted Answer

NA

Question 41

The cavities in teeth is often filled with alloy of metals to avoid bacterial infections. However when a person with dental filling ehew an active metal like aluminium foil acceidently he experiences severe pain in teeth. The pain is due to a spontaneous discharge of a galvanic cell reaction which is set inside the mouth of person. The active metal serve as anode and dental filling act as inert electrode on which reduction of `O_(2)` gas takes place. `E_(Al^(3+)|Al)^(@)=-1.66` volt `E_(O_(2)H^(+)|H_(2)O)^(@)=+1.23` volt What is the net cell reaction assuming acidic conditions in the mouth?A. `4Al(s)+3O_(2)(g)+6H_(2)Orarr4Al(OH)_(3)(s)`B. `4Al(s)+2O_(2)(g)+8H^(+)(aq)rarr4Al^(3+)+4H_(2O`C. `4Al(s)+3O_(2)(g)+12H^(+)(aq)rarr4Al^(3+)(aq)+6H_(2)O`D. `4Al(s)+3O_(2)(g)rarr2Al_(2)O_(3)(s)`

Accepted Answer

NA

Question 42

`Ag^(aq) + e^(-) rightarrow Ag(s)` `[email protected]) = 0.80 V` `Mg^(2+)(aq) + 2e^(-) rightarrow Mg(s)` `E^(@) = -2.73 V` Use the equations above to calcualte the value or `DeltaG^(@0` (in kJmol) for the reaction `Mg(s) + 2Ag^(+)(aq) rightarrow Mg^(2+)(aq) + 2Ag(s)`A. 681B. 341C. `-341`D. `-681`

Accepted Answer

NA

Question 43

`Ag^(aq) + e^(-) rightarrow Ag(s)` `[email protected]) = 0.80 V` `Mg^(2+)(aq) + 2e^(-) rightarrow Mg(s)` `E^(@) = -2.73 V` Use the equations above to calcualte the value or `DeltaG^(@0` (in kJmol) for the reaction `Mg(s) + 2Ag^(+)(aq) rightarrow Mg^(2+)(aq) + 2Ag(s)`A. 681B. 341C. `-341`D. `-681`

Accepted Answer

NA

Question 44

The limiting molar conductivity of KCl `KMO_(3)` and `AgNO_(3)` are 149.9145.0 and 133.4 S `cm^(2) mol^(-1)` respectively at `25^(@)C`. The limiting molar conductivity of AgCl at the same temperature in S `cm^(2) mol^(-1)` isA. 128.5B. 138.3C. 161.5D. 253.3

Accepted Answer

NA

Question 45

It takes 126.5 minutes using a current of 5.15 A to deposit all of the nickel from 225mL of a solution contaiing `Ni^(2+)`. What was the original concentration of `Ni^(2+)` in the solution?A. 3.60MB. 1.80MC. 0.900MD. `1.50xx10^(-2)M`

Accepted Answer

NA

Question 46

The specific conductance of a N10 KCl at `25^(@)C` is 0.0112 `ohm^(-1) cm^(-1)`. The resistance of cell contaiing solution at the same temperature was found to be 55 ohms. The cell contant will beA. `6.16cm^(-1)`B. `0.616cm^(-1)`C. `0.0616cm^(-1)`D. `616cm^(-1)`

Accepted Answer

NA

Question 47

`2Ce^(4+) + Co rightarrow 2Ce^(3+) + Co^(2+) E_(cell)^(@) = 1.89V` `E_(Co^(2+)Co)^(@) = -0.277V`. Hence `E_(Ce^(4+)Ce^(3+))^(@)` isA. 0.805VB. 1.613VC. `-0.805V`D. `-1.613V`

Accepted Answer

NA

Question 48

The highest electrical conductivity of the following aqueous solutions is ofA. 0.1 M acetic acidB. 0.1M chloroacetic acidC. 0.1 M fluoroacetic acidD. 0.1 M difluoroacetic acid

Accepted Answer

NA

Question 49

Which 0.10M aqueous solutin exhibits the lowest electrical conductivity?A. `NH_(4)Cl`B. `CuBr_(2)`C. `Na_(2)CO_(3)`D. `C_(2)H_(6)OH`

Accepted Answer

NA

Question 50

The reduction potential of a half-cell consisting of a Pt electrode immersed in `1.5 M Fe^(2+)` and ` 0.015 M Fe^(3+)` solutin at `25^@ C` is `(E_(Fe^(3+)Fe^(2+))^@ = 0.770 V)` is .A. 0.21 VB. 0.88VC. 0.710VD. 0.850V

Accepted Answer

NA

Explore topic-wise InterviewSolutions in .

The EMF of the following cell: `Zn| Zn^(2+)(0.1M) || Cl^(-)(0.01M) | AgCl | Ag` is: [Given : E_(Zn^(2+)|/Zn)^(@) = -0.76V`, `E_(Cl^(-)| AgCl|Ag)^(@)` = 0.22 V`, `(2.303RT)/(F) = 0.06]`A. 0.96 VB. 0.345 VC. 1.23D. 1.13 V

`DeltaG^(@)` of the cell reaction `AgCl(s) + 1/2H_(2) rightarrow Ag(s) + H^(+) + Cl^(-)` is `-21.52kJ`. `DeltaG^(@)` of 2AgCl(s) + H_(2)(g) rightarrow + 2H^(+) + 2Cl^(-)` isA. `-21.52kJ`B. `-10.76 kJ`C. `-43.04kJ`D. `43.04 kJ`

For the electrolytic production of `NaClO_(4)` from `NaClO_(3)` as per the following equation: `NaClO_(3) + H_(2)O rightarrow NaClO_(4) + H_(2)` How many faradays of electricity will be required to produce 0.5 "mole" of `NaClO_(4)` assuming 60% efficiency?A. 0.835 FB. 1.67 FC. 3.34 FD. 1.6 F

Which process occurs in the electrolysis of an aqueous tin (II) chloride solution at a tin anode?A. Sn = `Sn^(2+) + 2e^(-)`B. `2Cl^(-) = Cl_(2) + 2e^(-)`C. `2H_(2)O = O_(2) + 4H^(+) + 4e^(-)`D. None of these

How many electrons flow when a current of 5 amperes is passed through a conductor for 200 seconds?A. `6.241 xx 10^(21)`B. `6.0241 xx 10^(21)`C. `6.241 xx 10^(22)`D. `6.0241 xx 10^(20)`

The number of electrons delivered at the cathode during electrolysis by a current of `1` ampere in 60 seconds is (charger on electron `= 1.60 xx 10^(-19)C`)A. `3.74 xx 10^(20)`B. `6.0 xx 10^(23)`C. `7.48 xx 10^(21)`D. `6.0 xx 10^(20)`

During discharge of a lead storage cell the density of sulphuric acid in the cell:A. increasesB. decreasesC. remains unchangedD. initially increases but decreases subsequently

Rechargable batteries include which of the those below? (P) Dry cell (Q) Lead-acid storage battery (R ) Nickel -cadmium batteryA. Q onlyB. P and Q onlyC. Q and R onlyD. P,Q and R only

A 3.00amp current is used to electrolyze the molten chlorides, `CaCl_(2),MgCl_(2),AlCl_(3)` and `FeCl_(3)`. The deposition of which mass of metal will require the longest electrolysis time?A. 100g CaB. 50g MgC. 75g AlD. 125g Fe

When connected to a Standard Hydrogen Electrode (SHE) electrons flow from an unknown half cell to the SHE. Which statement is correct?A. The unknown half cell is the anode.B. Oxidation occurs at the SHE.C. `E_(red)^(@)` for the unknown half cell is positive.D. `E_(cell)^(@)` is negative.

Given these standards reduction potentials, what is the free energy change (in kJ. Mol^(-) for the reaction: `Pb(s) + 2Ag^(+)(aq) rightarrow Pb^(2+)(aq) + 2Ag(s)` `Ag^(+)(aq) + e^(-) rightarrow Ag(s)` `E^(@) = 0.80V` `Pb^(2+)(aq) + 2e^(-) rightarrow Pb(s)` `E^(@) = -0.13V`A. -180B. -90C. 90D. 180

Given these standard reduction potentials, what is the standard reduction potential for `Co^(3+)(aq) + 3e^(-) rightarrow Co(s)`? `Co^(3+)(aq) + e^(-) rightarrow Co^(2+)(aq) E^(@) = 1.82V` `Co^(2+)(aq) + 2e^(-) rightarrow Co(s) E^(@) = -0.28V`A. 2.10VB. 1.54vC. 1.26vD. 0.42V

By the electrolysis of aqueous solution of `CuSO_(4)`, the products obtained at both the inert electrodess are:A. `O_(2)` at anode and `H_(2)` at cathode.B. `H_(2)` at anode and Cu at cathodeC. `O_(2)` at anode and Cu at cathodeD. `H_(2)S_(2)O_(8)` at anode and `O_(2)` cathode.

During the electrolysis of aqueous zinc nitrate.A. Zn plates out at the cathodeB. Zn plats out at the anodeC. `H_(2)` gas is evolved at the anodeD. `O_(2)` gas is evolved at the anode.

`Ag^(aq) + e^(-) rightarrow Ag(s)` `[email protected]) = 0.80 V` `Mg^(2+)(aq) + 2e^(-) rightarrow Mg(s)` `E^(@) = -2.73 V` Use the equations above to calcualte the value or `DeltaG^(@0` (in kJ/mol) for the reaction: `Mg(s) + 2Ag^(+)(aq) rightarrow Mg^(2+)(aq) + 2Ag(s)`A. 681B. 341C. `-341`D. `-681`

`Ag^(aq) + e^(-) rightarrow Ag(s)` `[email protected]) = 0.80 V` `Mg^(2+)(aq) + 2e^(-) rightarrow Mg(s)` `E^(@) = -2.73 V` Use the equations above to calcualte the value or `DeltaG^(@0` (in kJ/mol) for the reaction: `Mg(s) + 2Ag^(+)(aq) rightarrow Mg^(2+)(aq) + 2Ag(s)`A. 681B. 341C. `-341`D. `-681`

The limiting molar conductivity of KCl, `KMO_(3)` and `AgNO_(3)` are 149.9,145.0 and 133.4 S `cm^(2) "mol"^(-1)`, respectively at `25^(@)C`. The limiting molar conductivity of AgCl at the same temperature in S `cm^(2) "mol"^(-1)` is:A. 128.5B. 138.3C. 161.5D. 253.3

It takes 126.5 minutes using a current of 5.15 A to deposit all of the nickel from 225mL of a solution contaiing `Ni^(2+)`. What was the original concentration of `Ni^(2+)` in the solution?A. 3.60MB. 1.80MC. 0.900MD. `1.50xx10^(-2)M`

The specific conductance of a N/10 KCl at `25^(@)C` is 0.0112 `ohm^(-1) cm^(-1)`. The resistance of cell contaiing solution at the same temperature was found to be 55 ohms. The cell contant will be:A. `6.16cm^(-1)`B. `0.616cm^(-1)`C. `0.0616cm^(-1)`D. `616cm^(-1)`

`2Ce^(4+) + Co rightarrow 2Ce^(3+) + Co^(2+), E_(cell)^(@) = 1.89V` `E_(Co^(2+)//Co)^(@) = -0.277V`. Hence `E_(Ce^(4+)//Ce^(3+))^(@)` isA. 0.805VB. 1.613VC. `-0.805V`D. `-1.613V`

The highest electrical conductivity of the following aqueous solutions is ofA. 0.1 M acetic acidB. 0.1M chloroacetic acidC. 0.1 M fluoroacetic acidD. 0.1 M difluoroacetic acid

Which 0.10M aqueous solutin exhibits the lowest electrical conductivity?A. `NH_(4)Cl`B. `CuBr_(2)`C. `Na_(2)CO_(3)`D. `C_(2)H_(6)OH`

The reduction potential of a half-cell consisting of a Pt electrode immersed in `1.5 M Fe^(2+)` and ` 0.015 M Fe^(3+)` solutin at `25^@ C` is `(E_(Fe^(3+)//Fe^(2+))^@ = 0.770 V)` is .A. 0.21 VB. 0.88VC. 0.710VD. 0.850V

1.	The EMF of the following cell: `Zn\| Zn^(2+)(0.1M) \|\| Cl^(-)(0.01M) \| AgCl \| Ag` is: [Given : E_(Zn^(2+)\|/Zn)^(@) = -0.76V`, `E_(Cl^(-)\| AgCl\|Ag)^(@)` = 0.22 V`, `(2.303RT)/(F) = 0.06]`A. 0.96 VB. 0.345 VC. 1.23D. 1.13 V
Answer» Correct Answer - D

2.	`DeltaG^(@)` of the cell reaction `AgCl(s) + 1/2H_(2) rightarrow Ag(s) + H^(+) + Cl^(-)` is `-21.52kJ`. `DeltaG^(@)` of 2AgCl(s) + H_(2)(g) rightarrow + 2H^(+) + 2Cl^(-)` isA. `-21.52kJ`B. `-10.76 kJ`C. `-43.04kJ`D. `43.04 kJ`
Answer» Correct Answer - C

3.	The emf of the cell `Zn\|ZnCl_(2)` (0.05M) \| AgCl(s)`,Ag is 1.015 V at 298 K and the temperature coefficient of its emf is `-4.92 xx 10^(-4)` V/K. How many of the reaction thermodynamic parameter `DeltaG`, `DeltaS` and `DeltaH` are negative at 298 K?A. None of themB. One of themC. Two of themD. All of them
Answer» Correct Answer - B

5.	Based on the data given below, the correcy order of reducing power is: `Fe_((aq.))^(3+) + e rarr Fe_((aq.))^(2+), E^(@) = +0.77 V` `Al_((aq.))^(3+) + 3e rarr Al_((s)), E^(@) = -1.66 V` `Br_(2(aq.)) + 2e rarr 2Br_((aq.))^(-), E^(@) = +1.08 V`A. `Br^(-) lt Fe(2+) lt Al`B. `Fe^(2+) lt Al lt Br^(-)`C. `Al lt Br^(-) lt Fe^(2+)`D. `Al lt Fe^(2+) lt Br^(-)`
Answer» Correct Answer - A

13.	The potential of the Daniel cell, `Zn \|(ZnSO_(4))\|\|(CuSO_(4)\|Cu` was reported by Buckbee, Surdzial and Metz as `E^(@) = 1.1028 - 0.641 xx 10^(-3)T` + `0.72 xx 10^(-5)T^(2)`, where T is the temperature in degree celcius, Calcualte `DeltaS^(@0` for the cell reaction at `25^(@)C`.A. `-45.32 EU`B. `-34.53 EU`C. `-25.43 EU`D. `54.23 EU`
Answer» Correct Answer - D

18.	Statement-1: Absolute value of `E_("red")^(@)` of an electrode cannot be determined. statement-2: Neither oxidation nor reduction can take place alone.A. Statement-1 is True, Statement-2 is True : Statement-2 is a correct explanation for Statement-2B. Statement-1 is True, Statement-2 is True : Statement-2 is `NOT` a correct explanation for Statement-2C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True.
Answer» Correct Answer - B

20.	Statement-1: The electrode potential of SHE is zero only at `25^(@)C` and not at any other temperature. Statement-2: SHE is standard reference electrode.A. Statement-1 is True, Statement-2 is True : Statement-2 is a correct explanation for Statement-1B. Statement-1 is True, Statement-2 is True : Statement-2 is `NOT` a correct explanation for Statement-1C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True.
Answer» Correct Answer - D

36.	Which of the following are correct in acidic medium?A. The oxidising power of `KMnO_(4)` will increase with increase in pHB. The oxidising power of `KMnO_(4)` will decrease with increase in pHC. The oxidising of `K_(2)Cr_(2)O^(7)` will increase with increase in pHD. The oxidising power of `K_(2)Cr_(2)O^(7)` will decrease with increase in pH
Answer» Correct Answer - B::D

37.	Which of the following statement(s) is/are correct?A. The equilibrium constant of cell reaction in a concentration cell is 1B. Activity of a radioactive nucleus is temperature independent.C. Limiting molar conductivities `(A_(m)^(-))` of NaCl and KCl are different due to difference in ionic mobilities of `Na^(+)` (aq) and `K^(+)` (aq) ions.D. When aq. Solution of 2Mj-HCl is electrolysed, more `H^(+)` ions are reduced at cathode than `Cl^(-)` ions at anode due to higher ionic mobility of `H^(+)` (aq) ions.
Answer» Correct Answer - A::B::C

38.	Choose the correct statement(s)A. Cell constant values of conductivity cells are independent of the solution filled into the cell.B. Kohlrausch law is valid for strong eletrolyte but not for weak electrolyte.C. In general conductivity decreases on dilution whereas equivalent and molar conductivity increase on dilution.D. Salt bridge is employed to maintain the electrical neutrality and to minimize the liquid -liquid junction potential.
Answer» Correct Answer - A::C::D