Question

I am a bit confused. My openstax textbook states:

When the half-cell X is under standard-state conditions, its potential is the standard electrode potential, E°X. Since the definition of cell potential requires the half-cells function as cathodes, these potentials are sometimes called standard reduction potentials.

I would greatly appreciate if someone can explain to me why the half cell has to be a cathode if the measured reduction table has both positive and negative values.

Answer 1

The standard electrode potential, E°x, measures the tendency of a half-cell to undergo reduction and is sometimes called the standard reduction potential. The cathode and anode in a cell are determined based on their reduction potentials. The sign of the reduction potential indicates the spontaneity of the cell reaction.

Step-by-step explanation:

The standard electrode potential, E°x, is a measure of the tendency of a half-cell to undergo reduction when connected to a standard hydrogen electrode acting as an anode.

When measuring cell potential, the half-cell with the higher reduction potential is considered the cathode, while the other half-cell is the anode.

The standard electrode potentials are sometimes called standard reduction potentials because they reflect the tendency for reduction to occur in a half-reaction.

These potentials can be positive or negative, and the arithmetic sign signifies the spontaneity of the cell reaction.