Question

Write the cell reaction of a lead storage battery when it is discharged. How does the density of the electrolyte change when the battery is discharged ?

Answer 1

The cell reaction of a lead storage battery when it is discharged, may be given as :
`Pb(s)+PbO_(2)(s)+4H^(+)(aq)+2SO_(4)^(2-)(aq) to 2PbSO_(4)+2H_(2)O(l)`
Density of the electrolyte i.e. conc. `H_(2)SO_(4)` solution decreases because of the dilution of electrolyte taking place since water is formed as one of the products.