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 ?

Explanation

* The discharging reaction of lead storage cell is as follows :
`Pb_((S))+PbO_(2(S))+2H_(2)SO_(4(aq)) to 2PbSO_(4(S))+2H_(2)O_((l))`
* Density of electrolyte get decreases when discharging is going on. Initially 38% `H_(2)SO_(4)` is taken as electrolytic in battery. `H_(2)SO_(4)` has more density than water.
* In this reaction `H_(2)SO_(4)` is utilized and water is formed. so the density of electrolyte decreases.