NEET Chemistry Electrochemistry Online Test Set D

1. Electrode potential for the following half-cell reactions are Zn → Zn2+ + 2e-; E° = +0.76 V; Fe → Fe2+ + 2e-; E = + 0.44 V The EMF for the cell reaction Fe2+ + Zn → Zn2+ + Fe will be 0.44-0.76 (1) - 0.32 V (2) + 1.20 V (3) - 1.20 V (4) + 0.32 V

2. An electrochemical cell is set up as : Pt; H₂(1 atm) |HCl (0.1 M) || CH₃COOH (0.1M) | H₂(1 atm) ; Pt. The e.m.f. of this cell will not be zero, because

3. To protect iron against corrosion, the most durable metal plating on it, is

4. Standard reduction potentials at 25°C of Li+ Ba2+ / Ba, Na+/Na and Mg2+ / Mg are -3.05, -2.90 -2.71 and -2.37 volt respectively. Which one of the following is the strongest oxidizing agent?

5. A solution contains Fe²⁺, Fe³⁺ and I^- ions. This solution was treated with iodine at 35°C. E° for Fe³⁺/Fe²⁺ is +0.77 V and E° for I₂/2I^- = 0.536 V. The favourable redox reaction is

6. 4.5g of aluminium (at. mass 27 amu) is deposited at cathode from Al³⁺ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H⁺ ions in solution by the same quantity of electric charge will be

7. A hypothetical electrochemical cell is shown below A|A⁺(xM)||B⁺(yM)|B, the emf measured is +0.20 V. The cell reaction is

8. the standard EMF of the reactionwill be

9. The efficiency of a fuel cell is given by

10. The equilibrium constant of the reaction; Cu(s)+2Ag + (aq)⟶Cu 2+ (aq)+2Ag(s) E o =0.46V at 298K

11. On the basis of the following E° values, the strongest oxidizing agent is

12. 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 value of E0cell for the pentane-oxygen fuel cell is

13. Kohlrausch's law states that at

14. The equivalent conductance of M/32 solution of a weak monobasic acid is 8.0 mhos cm² and at infinite dilution is 400 mhos cm². The dissociation constant of this acid is

15. Al₂O₃ is reduced by electrolysis at low potentials and high currents. If 4.0 x 10⁴ amperes of current is passed through molten Al₂O₃, for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency, at. mass of Al = 27 g mol^-1)

16. Given : (i) Cu²⁺ + 2e^- → Cu, E° = 0.337 V, (ii) Cu²⁺ + e^- → Cu⁺, E° = 0.153 V, Electrode potential, E° for the reaction, Cu⁺ + e^- → Cu, will be

17. Consider the following relations for emf of a electrochemical cell (a) emf of cell = (Oxidation potential of anode) (Reduction potential of cathode) (b) emf of cell = (Oxidation potential of anode) + (Reduction potential of cathode) (c) emf of cell = (Reductional potential of anode) + (Reduction potential of cathode) (d) emf of cell = (Oxidation potential of anode) (Oxidation potential of cathode) Which of the above relations are correct?

18. For the reduction of silver ions with copper metal, the standard cell potential was found to be +0.46V at 25C. The value of standard Gibbs energy, will be (F = 96500 C mol^-1)

19. An increase in equivalent conductance of a strong electrolyte with dilution is mainly due to

20. 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 state are connected to make a cell. The cell potential will be

21. The Gibb's energy for the decomposition of Al₂O₃at 500°C is as follows The potential difference needed for the electrolytic reduction of aluminium oxide (Al₂O₃) at 500°C is at least

22. Molar conductivitiesat infinite dilution of NaCl, HCl and CH₃COONa are 126.4, 425.9 and 91.0 S cm²mol^-1 respectivelyfor CH₃COOH

23. Standard reduction potentials of the half reactions are given below The strongest oxidising and reducing agents respectively are

24. Limiting molar conductivity ofis equal to

25. 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 atm pressure. The oxidation potential of electrode would be?

26. At 25°C 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 conductance is 238 ohm^-1 cm² mol^-1. The degree of ionisation of ammonium hydroxide at the same concentration and temperature is

27. A button cell used in watches functions as following The cell potential will be

28. The weight of silver (At. Wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O₂ at STP will be

29. When 0.1 molis oxidised the quantity of electricity required to completely oxidise is

30. A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as