Compare the use of a dry cell battery with button cell battery in terms of the chemistry, cost and practicality, impact on society and environment.

The dry cell or Leclanche cell was the first commercial battery and therefore had a big impact on society. It is the most common and the cheapest of the commercially available cell and is most widely used in torches, portable radios and battery-operated clocks. It is best used for low drain appliances, which need only small currents such as portable items (radio). It consists of a zinc outer casting, the anode, an aqueous paste of …

…Zn(OH)2 (s) + 2e-<Tab/> The reduction process at the cathode is: HgO(s) + H2O(l) + 2e- → Hg(l) + 2OH-(aq) In terms of environmental impact, the button cell has more problems than the dry cell as the disposal releases toxic mercury into the environment. Very few of these cells are produced now because of the manufacturing and disposal problems introduced by the presence of mercury or mercuric oxide.