Question 1:Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn | |
Question 2:Given the standard electrode potentials, K+/K = −2.93V, Ag+/Ag = 0.80V, Hg2+/Hg = 0.79V Mg2+/Mg = −2.37 V, Cr3+/Cr = − 0.74V Arrange these metals in their increasing order of reducing power. | |
Question 3:Depict the galvanic cell in which the reaction Zn(s) + 2Ag+(aq) → Zn2+(aq) + 2Ag(s) takes place. Further show: (i) Which of the electrode is negatively charged? (ii) The carriers of the current in the cell. (iii) Individual reaction at each electrode. | |
Question 4:Calculate the standard cell potentials of galvanic cells in which the following reactions take place: (i) 2Cr(s) + 3Cd2+(aq) → 2Cr3+(aq) + 3Cd (ii) Fe2+(aq) + Ag+(aq) → Fe3+(aq) + Ag(s) Calculate the =∆rGθ and equilibrium constant of the reactions. | |
Question 5:Write the Nernst equation and emf of the following cells at 298 K: (i) Mg(s) | Mg2+(0.001M) || Cu2+(0.0001 M) | Cu(s) (ii) Fe(s) | Fe2+(0.001M) || H+(1M)|H2(g)(1bar) | Pt(s) (iii) Sn(s) | Sn2+(0.050 M) || H+(0.020 M) | H2(g) (1 bar) | Pt(s) (iv) Pt(s) | Br2(l) | Br−(0.010 M) || H | |
Question 6:In the button cells widely used in watches and other devices the following reaction takesplace: Zn(s) + Ag2O(s) + H2O(l) → Zn2+(aq) + 2Ag(s) + 2OH−(aq) Determine and for the reaction. | |
Question 7:Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration. | |
Question 8:The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 Scm−1. Calculate its molar conductivity. | |
Question 9:The resistance of a conductivity cell containing 0.001M KCl solution at 298 K is 500M. What is the cell constant if conductivity of 0.001M KCl solution at 298 K is 0.146 × 10−3S cm−1. | |
Question 10:The conductivity of sodium chloride at 298 K has been determined at different concentrations and the results are given below:
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Question 11: Conductivity of 0.00241 M acetic acid is 7.896 × 10−5 S cm−1. Calculate its molar conductivity and if for acetic acid is 390.5 S cm2 mol−1, what is its dissociation constant? | |
Question 12:How much charge is required for the following reductions: (i) 1 mol of Al3+ to Al. (ii) 1 mol of Cu2+ to Cu. (iii) 1 mol of MnO4– to Mn2+. | |
Question 13:How much electricity in terms of Faraday is required to produce (i) 20.0 g of Ca from molten CaCl2. (ii) 40.0 g of Al from molten Al2O3. | |
Question 14: How much electricity is required in coulomb for the oxidation of (i) 1 mol of H2O to O2. (ii) 1 mol of FeO to Fe2O3. | |
Question 15: A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode? | |
Question 16:Three electrolytic cells A,B,C containing solutions of ZnSO4, AgNO3 and CuSO4, respectively are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell B. How long did the current flow? What mass of copper and zinc were deposited? | |
Question 17: Using the standard electrode potentials given in Table 3.1, predict if the reaction between the following is feasible: (i) Fe3+(aq) and I−(aq) (ii) Ag+ (aq) and Cu(s) (iii) Fe3+ (aq) and Br−(aq) (iv) Ag(s) and Fe3+(aq) (v) Br2 (aq) and Fe2+ (aq). | |
Question 18: Predict the products of electrolysis in each of the following: (i) An aqueous solution of AgNO3 with silver electrodes. (ii) An aqueous solution of AgNO3with platinum electrodes. (iii) A dilute solution of H2SO4with platinum electrodes. (iv) An aqueous solution of CuCl2 with platinum electrodes. | |