Question Bank 456y41

Question Bank PART–A (2 Mark Question) 1. Define electrochemical cell. Give two examples. 2. Write about conductivity of electrolytes. 3. What are the conditions for an electrochemical cell to act as a standard cell? 4. Distinguish between galvanic cell and electrolytic cell. 5. What is electrode potential? How is it developed? 6. Distinguish between reversible and irreversible cell giving one example for each. 7. How emf of a cell is mesuared? Represent a galvanic cell according to IUPAC convention. 8. How will you predict the spontaneity of any redox system using emf? 9. Write Nernst equation for M → Mn+ +ne10. What is reference electrode?Give any two examples. 11. Define: (a) Single electrode potential and (b) Standard electrode potential. What are the factors affecting it? 12. Galvanized containers are not used for storage of food products, but tin coated containers are used. Give reason. 13. Why salt bridge is used in the construction of a cell? 14. Mention the applications of conductometric titrations. 15. Define the emf of the electrochemical cell (or) what is electrode potential? 16. What is ion selective electrode? Give example. Mention the applications of ion selective electrode. 17. What is a reversible cell? Give examples. 18. State whether Zn spatula can be used to stir a solution of CuSO4 or not and justify your answer. 19. Why pure iron does not dissolve readily in conc.HNO3? 20. Mention the applications of Nernst equation. 21. What is irreversible cell? Give examples.

22. List the six applications of electrochemical series. 23. Draw and explain the representative plot of conductometric titration of a strong acid versus strong base. 24. Draw and explain the representative plots of potentiometric titration of a ferrous ion with permanganate ions. 25. Zn(s) + H2SO4 ↔ ZnSO4(aq) + H2(g). Justify your whether this cell is an irreversible cell or not. PART–A (2 Mark Problems) 1. Calculate the standard emf of a Daniel cell at 25 ℃ when the concentration of the ZnSO4 and CuSO4 are 0.001 M and 0.1 M respectively. The standard potential of cell is 1.1 volts. 2. A zinc rod is placed in 0.1 M ZnSO4 solution at 298 K. write the electrode reaction and calculate the potential of the electrode. E0(Zn2+, Zn) = -0.76 V. 3. Calculate the half cell potential at 298 K for the reaction Zn2+(aq) + 2e- → Zn(s), if [Zn2+] = 5M and E0(Zn2+, Zn) = -0.76 V. 4. Write the cell reaction and calculate E0 for the cell Zn, Zn2+ (1 M) || Cu2+ (0.1 M), Cu. 5. What is the potential of a lead electrode that is in with a solution of 0.015 M in Pb2+ ions? The standard electrode potential of Pb à Pb2+ + 2 e- is equal to +0.13 V. 6. Calculate the reduction potential of lead electrode in with a solution of 0.018 M Pb2+ ions (the standard electrode potential E0 = -0.13 V). 7. Calculate the single electrode potential of copper immersed in 0.01 M CuSO4 solution at 25 0C. E0Cu/Cu2+= +0.34 V. PART–B (Big Questions) 1. Derive Nernst equation for single electrode potential and explain the involved in it. Write its applications. 2. Define emf series. Discuss the applications of emf series. 3. What is glass electrode? How will you construct & use it to measure the pH of the given solution? (or) How pH is determined using reference electrode? 4. Discuss the conductometric titrations. What are the advantages of conductometric titration over ordinary volumetric titrations? 5. Describe the construction and working of hydrogen and calomel electrode.

6. What is the principle of potentiometric titrations? How it is useful to find the equivalence point by potentiometric method? PART–B (Problem) 1. Construct a galvanic cell and present the cell equations and find out the feasibility of the cell. Given that standard reduction potential of Zn2+/Zn (0.01 M) = -0.76 V and Cu2+ / Cu (0.1 M) = 0.34V. 2. Calculate the emf of the concentration cell consisting of zinc electrodes, one immersed in a solution of a 0.02 M and the other immersed in 0.001 M solution of its ions at 25 0C. 3. Find the potential of the cell in which the following reaction take place at 250C. Zn + Cu2+(0.02M) → Zn2+(0.4M) + Cu. Given E0(Zn2+, Zn) = -0.76 V, E0(Cu2+, Cu) = 0.34 V. 4. Consider the cell reaction Zn(s) + Fe2+(0.005M) Zn2+(0.01M) + Fe(s). Given that the standard emf of the cell is 0.323 V at 250C. (a) Construct the cell and (b) calculate the emf of the cell. 5. Calculate the emf of the following cell. Zn | Zn2+ || Ag+ | Ag, where [Zn2+]=0.1 M, [Ag+] = 0.01, EAg0 = +0.8 V, EZn0 = +0.8 V. 6. Calculate the half cell potential at 298 K for the reaction Zn2+ (aq) + 2e- à Zn(s) if [Zn2+] is 5.0 M and E0Zn2+/Zn = -0.76 V. 7. For electrochemical cell Fe | Fe2+ (0.1M) || Cd2+ (0.001M) | Cd, write the cell reaction. Calculate the emf of the cell at 25 0C. Calculate standard free energy and equilibrium constant of the cell reaction. The standard electrode potential of iron and cium electrode is -0.44 V and -0.40 V respectively. 8. Two lead rods are placed in lead salt solutions of concentration 0.005 M and 0.05 M respectively to form a cell. Calculate its emf at 298 K. 9. The potential of the cell Pt | H2 (g)|| HCl (g) | AgCl(s) | Ag is 0.322 V at 25 0C. What is the pH of the electrolyte solution? (E0Ag-AgCl = +0.22V) 10. Balance the equation and calculate the equilibrium constant for the reaction. Fe2+ (aq) + Au3+ (aq) ↔ Fe3+ (aq) + Au+ (aq). Given that E0Au+/Au = +1.69V, E0Fe3+/Fe = +0.77 V. 11. Calculate the emf of the following cell. The standard reduction potential of zinc and copper electrodes are -0.76 V and +0.34 V respectively. Zn | Zn2+ (0.1 M) || Cu2+ (0.1 M) | Cu. 12. Calculate the emf of the following galvanic cell. The standard reduction potential of zinc and copper electrodes are -0.76 V and +0.34 V respectively. Zn | Zn2+ (0.1 M) || Cu2+ (0.01 M) | Cu

13. Calculate the emf of the following electrochemical cell at 25 0C. Cu, Cu2+ (0.1 M) ||H+ (0.01 M), H2 (1 atm); Pt. given that E0Cu2+/Cu= +0.34 V and E0H+/H = 0.0 V.