A lead storage cell is discharged which causes the `H_(2)SO_(4)` electrolyte to change from a concentration of `34.6%` by weight (density `1.261 gmL^(-1)` at `25^(@)C`) to one of `27%` by weight. The original volume of electrolyte is one litre. How many faraday have left the anode of battry ? Note the water is produced by the cell reaction as `H_(2)SO_(4)` is used up. Over all reaction is :
`Pb_(s) + PbO_(2) + 2H_(2)SO_(4(l)) rarr 2PbSO_(4(s)) + 2H_(2)O`