Dry-Cell Batteries

• The most inexpensive type of dry cell is composed of a zinc case that acts as the anode. The zinc is oxidized.
• The cathode is a carbon rod immersed in a moist paste of MnO2 that also contains NH4Cl. The MnO2 is reduced to Mn2O3.
• These two half-reactions produce a voltage of about 1.5 volts.
• Two or more of these batteries can be connected in series to produce higher voltages.