1. VOLTAGE (CELL POTENTIAL)
Voltage is commonly used as a short name for electrical potential difference .its
corresponding SI unit is Volts. The voltage between the two electrodes is denoted
by (VC-VA), can be directly measured by voltmeter.
The theoretical standard cell voltage can be determined using Eo values:
Eo (cathodic) – Eo (anodic) = Eo (cell)
The theoretical cell voltage is modified by the Nernst equation,
1. If the difference in the standard electrode potential is more, higher is the
emf of the cell.
2. As the concentration of the product increases, the Ecell decreases
3. As the temperature increases, Ecell decreases.
The energy stored in a battery, called the battery capacity.
Battery capacity is a measure of the charge stored by a battery, determined by
the amount of electrical energy the battery can deliver over certain period and is
measured in Ampere-hour (Ah), capable of being provided by a battery during
discharge. (One Ah = current of one Ampere flowing for one hour).
The theoretical capacity may be calculated using faradays relation, C = WnF/M,
(where W is weight of the active material and M is the molecular mass of the
active material respectively) it is the number of moles of the electro active
material associated with the complete discharge of the cell.