Match List-I with List-II List-I Type of cell/Batteries List-II React…

The correct answer is Option (1) → (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Every cell in the list turns the energy of a redox reaction into electricity. They differ in how they are used: a primary battery works only once, because its reaction cannot be reversed, while a secondary battery can be recharged by passing current through it in the opposite direction; a fuel cell runs as long as the reactants are supplied.

• (A) Daniell cell — This matches (III) \(Zn(s) + Cu^{2+} (aq) \rightarrow Zn^{2+} (aq) + Cu (s)\). Zinc dips into zinc sulphate and copper into copper sulphate; zinc is oxidised at the anode and \( \ce{Cu^2+} \) is reduced at the cathode (E° = 1.1 V).

      \( \ce{Zn(s) -> Zn^2+(aq) + 2e-} \) (anode)
      \( \ce{Cu^2+(aq) + 2e- -> Cu(s)} \) (cathode)

• (B) Fuel Cell — This matches (I) \(2H_2(g) + O_2(g) \rightarrow 2H_2O (l)\). In the hydrogen–oxygen fuel cell the gases are bubbled through porous carbon electrodes into concentrated aqueous NaOH:

      \( \ce{2H2(g) + 4OH-(aq) -> 4H2O(l) + 4e-} \) (anode)
      \( \ce{O2(g) + 2H2O(l) + 4e- -> 4OH-(aq)} \) (cathode)

• (C) Primary Batteries — This matches (IV) \(Zn(Hg) + HgO(s) \rightarrow ZnO(s) + Hg(l)\). This is the mercury cell, a primary cell used in hearing aids and watches; its potential stays constant at about 1.35 V:

      \( \ce{Zn(Hg) + 2OH- -> ZnO(s) + H2O + 2e-} \) (anode)
      \( \ce{HgO(s) + H2O + 2e- -> Hg(l) + 2OH-} \) (cathode)

• (D) Secondary Batteries — This matches (II) \(Pb(s) + PbO_2(s) + 2H_2SO_4 (aq) \rightarrow 2PbSO_4 (s) + 2H_2O (l)\). This is the lead storage battery used in vehicles; on charging, the reaction runs backwards and regenerates Pb and \( \ce{PbO2} \):

      \( \ce{Pb(s) + SO4^2-(aq) -> PbSO4(s) + 2e-} \) (anode)
      \( \ce{PbO2(s) + SO4^2-(aq) + 4H+(aq) + 2e- -> PbSO4(s) + 2H2O(l)} \) (cathode)

Shortcut: (A)-(III) appears only in Option (1).