NEET
Chemistry
Electrochemistry
Previous Years Questions

Two half cell reactions are given below. $$C{o^{3 + }} + {e^ - } \to C{o^{2 + }},\,\,\,\,\,\,\,\,\,E_{C{o^{2 + }}/C{o^{3 + }}}^0 = - 1.81\,V$$ $$2A{l... Standard electrode potential for the cell with cell reaction Zn(s) + Cu2+(aq)$$\to$$Zn2+(aq) + Cu(s) is 1.1 V. Calculate the standard Gibbs energy c... At 298 K, the standard electrode potentials of Cu2+ / Cu, Zn2+ / Zn, Fe2+ / Fe and Ag+ / Ag are 0.34 V,$$-$$0.76 V,$$-$$0.44 V V and 0.80 V, respect... Given below are half cell reactions:$$MnO_4^ - + 8{H^ + } + 5{e^ - } \to M{n^{2 + }} + 4{H_2}O$$,$$E_{M{n^{2 + }}/MnO_4^ - }^o = - 1.510\,V{1...
Find the emf of the cell in which the following reaction takes place at 298 K Ni(s) + 2Ag+ (0.001 M) $$\to$$ Ni2+ (0.001 M) + 2Ag(s) (Given that E$$_{... The molar conductance of NaCl, HCl and CH3COONa at infinite dilution are 126.45, 426.16 and 91.0 S cm2 mol$$-$$1 respectively. The molar conductance o... The molar conductivity of 0.007 M acetic acid is 20 S cm2 mol$$-$$1. What is the dissociation constant of acetic acid? Choose the correct option.[$$\L...
On electrolysis of dil. sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be :
The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol-1) is :
For a cell involving one electron $$E_{cell}^\Theta$$ = 0.59 V at 298 K, the equilibrium constant for the cell reaction is : [Given that $${{2.303RT}... For the cell reaction 2Fe3+(aq) + 2I– (aq)$$ \to $$2Fe2+(aq) + I2(aq)$${E_{cell}^\Theta }$$= 0.24 V at 298 K. The standard Gibbs energy ($$\Delta ...
In the electrochemical cell : $$Zn\left| {ZnS{O_4}\left( {0.01\,M} \right)} \right|$$$$\left| {CuS{O_4}\left( {1.0M} \right)} \right|Cu,$$ the emf of ...
The molar conductivity of a 0.5 mol/dm3 solution of AgNO3 with electrolytic conductivity of 5.76 $$\times$$ 10$$-$$3 S cm$$-$$1 at 298 K is ...
Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because
The number of electrons delivered at the cathode during electrolysis by a current of 1 ampere in 60 seconds is (charge on electron = 1.60 $$\times$$...
During the electrolysis of molten sodium chloride, the time required to produce 0.10 mol of chlorine gas using a current of 3 amperes is
If the Eocell for a given reaction has a negative value, which of the following gives the correct relationships for the values of $$\Delta$$Go and Ke...
The pressure of H2 required to make the potential of H2-electrode zero in pure water at 298 K is
A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as
The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be
When 0.1 mol MnO$$_4^{2 - }$$ is oxidised the quantity of electricity required to completely oxidise MnO$$_4^{2 - }$$ to MnO$$_4^ -$$ is
How many gram of cobalt metal will be deposited when a solution of cobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (...
Consider the half-cell reduction reaction Mn2+ + 2e$$-$$ $$\to$$ Mn, Eo = $$-$$1.18 V Mn2+ $$\to$$ Mn3+ + e$$-$$, Eo = $$-$$ 1.51 V The $$E$$o f...
At 25oC molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is 9.54 ohm$$-$$1 cm2 mol$$-$$1 and at infinite dilution its molar condu...
A button cell used in watches function as following. Zn(s) + Ag2O(s) + H2O(l) $$\rightleftharpoons$$ 2Ag(s) + Zn2+(aq) + 2OH$$-$$(aq) If half cell p...
A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 10 and by passing hydrogen gas around the platinum wire at one ...
Standard reduction potentials of the half reactions are given below : F2(g) + 2e$$-$$ $$\to$$ 2F$$-$$(aq) ;   Eo = + 2.85 V Cl2(g) + 2e...
The Gibb's energy for the decomposition of Al2O3 at 500oC is as follows $${2 \over 3}$$ Al2O3 $$\to$$ $${4 \over 3}$$ Al + O2 $$\Delta$$rG = +960...
Molar conductivities $$\left( {\Lambda _m^o} \right)$$ at infinite dilution of NaCl, Hcl and CH3COONa are 126.4, 425.9 and 91.0 S cm2 mol$$-$$1 respec...
Limiting molar conductivity of NH4OH $$\left[ {} \right.$$i.e.  $$\Lambda _{m\left( {N{H_4}OH} \right)}^0$$$$\left. {} \right]$$ is equal to...
A solution contains Fe2+, Fe3+ and I$$-$$ ions. This solution was treated with iodine at 35oC. Eo for Fe3+/Fe2+ is + 0.77 V and Eo for I2/2I$$-$$ = 0...
Standard electrode potential of three metals X, Y and Z are $$-$$1.2 V, + 0.5 V and $$-$$ 3.0 V respectively. The reducing power of these metals will ...
Standard electrode potential for Sn4+/Sn2+ couple is + 0.15 V and that for the Cr3+/Cr couple is $$-$$ 0.74 V. These two couples in their standard sta...
The electrode potentials for Cu2+(aq) + e$$-$$ $$\to$$ Cu+(aq) and Cu+(aq) + e$$-$$ $$\to$$ Cu(s) are + 0.15 V and + 0.50 V respectively. The v...
Which of the following expressions correctly represents the equivalent conductance at infinite diluation of Al2(SO4)3. Given that $$\mathop \Lambda \l... Consider the following relations for emf of an electrochemical cell (i) EMF of cell = (Oxidation potential of anode)$$-$$(Reduction pote... An increase in equivalent conductance of a strong electrolyte with dilution is mainly due to For the reduction of silver ions with copper metal, the standard cell potential was found to be + 0.46 V at 25oC. The value of standard Gibb's energy,... Given : (i) Cu2+ + 2e$$- \to $$Cu, Eo = 0.337 V (ii) Cu2+ + e$$- \to $$Cu+, Eo = 0.153 V Ele... The equivalent conductance of M/32 solution of a weak monobasic acid is 8.0 mho cm2 and at infinite dilution is 400 mho cm2. The dissociation constant... Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0$$ \times $$104 amperes of current is passed through molten Al2O3 for 6 ... On the basis of the following Eo values, the strongest oxidizing agent is [Fe(CN)6]4$$- \to $$[Fe(CN)6]3$$-$$+ e$$-$$; Eo =$$-$$0.... Kohlrausch's law states that at Standard free energies of formation (in kJ/mol) at 298 K are$$-$$237.2,$$-$$394.4 and$$-$$8.2 for H2O(l), CO2(g) and pentane (g) respectively. The... The equilibrium constant of the reaction: Cu(s) + 2Ag+(aq)$$ \to $$Cu2+(aq) + 2Ag(s); Eo = 0.46 V at 298 K is ... The efficiency of a fuel cell is given by EoFe2+/Fe =$$-$$0.441 V and EoFe3+/Fe2+ = 0.771 V, the standard EMF of the reaction Fe + 2Fe3+$$ \to $$3Fe2+ will be... A hypothetical electrochemical cell is shown below.$$A\left| {{A^ + }\left( {xM} \right)} \right|\left| {{B^ + }\left( {yM} \right)} \right|B$$The e... 4.5 g of aluminium (at. mass 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produ... The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (At... The standard e.m.f. of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25oC. The equilibrium constant of the reaction wou... The e.m.f. of a Daniell cell at 298 K is E1. When the concentration of ZnSO4 is 1.0 M and that of CuSO4 is 0.01 M, the e.m.f. changed to E2. What is ... On the basis of the information available from the reaction, 4/3Al + O2$$ \to $$2/3Al2O3,$$\Delta $$G =$$-$$827 kJ mol$$-$$1 of O2, ... In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam Standard electrode potentials are Fe2+/Fe [Eo =$$-$$0.44] and Fe3+/Fe2+[ Eo = 0.77]; If Fe2+, Fe3+ and Fe blocks are kept together, then ... Equivalent conductances of Ba2+ and Cl$$-$$ions are 127 and 76 ohm$$-$$1 cm$$-$$1 eq$$-$$1 respectively. Equivalent conductance of BaCl2 at infinite ... For the disproportionation of copper 2Cu+$$ \to  Cu2+ + Cu, Eo is (Given Eo for Cu2+/Cu is 0.34 V and Eo for Cu2+/Cu+ is 0.15 V.)...
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