Match List I with List II. List I (Conversion) List II (Number of Faraday required) A. 1 mole of H _2 O to O _2 I. 3F B. 1 mol of MnO _4^- to Mn ^ 2+ II. 2F C. 1.5 mol of Ca from molten CaCl _2 III. 1F D. 1 mol of FeO to Fe _2 O _3 IV. 5F Choose the correct answer from the options given below :
A. A-II, B-IV, C-I, D-III
In conversion A, H_2O 1 2 O_2 + 2H^+ + 2e^-, the charge required for 1 mole of H_2O is 2F. In conversion B, MnO_4^- + 8H^+ + 5e^- Mn^ 2+ + 4H_2O, the oxidation state of Mn changes from +7 to +2, so the charge required for 1 mole of MnO_4^- is 5F. In conversion C, Ca^ 2+ + 2e^- Ca, the charge required for 1 mole of Ca is 2F. Therefore, the charge required for 1.5 moles of Ca is 1.5 2F = 3F. In conversion D, Fe^ 2+ Fe^ 3+ + e^-, the oxidation state of Fe changes from +2 in FeO to +3 in Fe_2O_3, so the charge required for 1 mole of FeO is 1F. Matching these values yields A-II, B-IV, C-I, D-III.
Related: Chemistry — Electrochemistry · All PYQ Banks