Question

The standard half-cell reactions of lead acid battery is: 2) Half-cell reduction reaction form: red 1.69 +4Ht +so +2ePbSO4,()+2H2O) РЬОог.0) Red (aq) -Ox. PbSO4.()+2e Pb)+SO -0.36 4.(aq) Pb()+PbO2.(s)+2H2SO4.(ag) Tot. 2PBSO4.()+ 2H20() 2.05 a) Determine the full cell reaction of lead acid batter and the total cell potential when discharging the battery. I b) The half-cell potentials are given according to a reference potential. Describe this reference potential. What is the point of a reference potential?

Answer 1

a) Discharging & Discharging of a lead acid battery - - In the discharged state both the positive and negative plates become lead() sulfate (PbSOy) and the electrolyte loses much of de dissolved sulfuric acid and becomes primarily water. The discharge process in driven by reduction in energy when aut cap) of the acid react with o sons of Pbo to form strong o-l1 bonde is Ho. At Cathode p fully discharged two identical lead sulfate plates At anode - Poult souley Pbsou tge (0.36) 2 Pbout sout) + 4H) + s é = Pbsols) 7242012) (1.690) - Pboy + Pblolt 24, sofa a pbsolat 2420 (8) Eiell Ereduction Boxidering 169 -0.36 = 1.330 b) The half cell potential of each o is defined with respect to Handard hydrogen electrode (SHE). Reference electrodo is an electrode having an accuratel maintained potential used as a refuence for measurement & by other electrodes ease of Reference electrode 9t is an electrode which has a table and well known olechode potential. There are mane ways reference electrodes are used. The simplest is when the relerince electrode is used as a half-cell to build a electro Chemical cell.