Cell potential is the difference in `"______"` between the two electrodes of a galvanic cell that cause charge to flow.

Options

A. Potential energy
B. Kinetic energy
C. internal energy
D. Enthalpy

Answer

A

Explanation

Work is needed to move electrons in a wire or tow move ions through a solution to an electrode. The sitution is analogous to pumping water form one point to anoter. Work must be expended to pump the water. The analogy may be extended. Water moves spontaneously form a point at high pressure to point at low pressure. thus, a pressure differnce is required.
The work expended in moving water through a pipe depends on the volume of water and the pressure differnece. The situ-ations with electicity is similar. An electric change moves spontaneously from a point at high electric potential (high electrical pressure) to a point at low electric potential (low electrical pressure). The work needed to move an electric chage through a conductor depends on the total charge noved and the potential difference i.e. the difference in elec-trical potential (electrical pressure) between two points.
The potential energy difference (or the potential difference is most conveniently decribed as potential, which is the potential energy per unit chartge. The `SI` unit of charge is the coulomb `(C)`, the `SI` unit of potential enerfy is the joule `(J)` and the `SI` unit of potential is the Volt `(V)`. The relationship between the three quantities is given by the equation.
`1 V = 1(J)/(C)`
or `1 J = 1 C xx 1 V`
where `1 C` is the amount of achge transferred when a current of `1` ampere `(A)` flows for `1` second `(s)`. [Since `1` watt (`W)` is `1 JS^(-1)`, the current passing through the buulb in `1s` is `1 C`.] When `1 C` of charge moves between two electrodes that differ in electrical potential by `1V, 1 J` of energy is released by the cell and can be used to do electrical work. Remember, the electrical work expended in moving a charge through a conductor is
Electrical work = charge `xx` potential difference