What are primary and secondary batteries ? Give one example for each.

Explanation

The batteries which after their use over a period of time, becomes dead and the cell reaction is completed and this cannot be reused again are called primary batteries.
Eg: Leclanche cell, dry cell.
Secondary battery : A secondary battery is the battery in which after it's use can be reachged and can be used again.
A good secondary battery undergoes large no. of discharging and charging cycles. Lead storage bettery is an example of secondary battery.
The cell reactions when the bettery is in use are
`Pb_((s))+SO_(4(aq))^(-2)to PbSO_(4(s))+2e^(-) ` (A node)
`PbO_(2(s))+ SO_(4(aq))^(-2) to 4H_((aq))^(+)+2e^(-)to PbSO_(4(s))+2H_(2)O_((l))` (Cathode)
Overall cell reaction is
`Pb_((s))+PbO_(2(s))+2H_(2)SO_(4(aq))to 2PbSO_(4(s))+2H_(2)O_((l))`