(A) Mercury cell contains HgO + KOH (moist).
(B) Lead storage battery contains 38%H2SO4
(C) Dry cell contains MnO2+C (touching cathode) and paste of NH4Cl+ZnCl2 (touching anode)
(D) Fuel cell (H2−O2) contains Concentrated aqueous KOH solution
(E) Ni-Cd storage cell contains KOH solution.