STANDARD POTENTIAL Meaning and
Definition
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Standard potential refers to the measure of the electric potential of a half-cell under specific conditions, commonly used as a reference point for comparing and predicting the behavior of electrochemical reactions. It represents the tendency of an electrode in a half-cell to gain or lose electrons during a redox reaction.
The standard potential is measured under a set of standardized conditions, including: a temperature of 25 degrees Celsius, a concentration of 1 molar for any solute, pressure of 1 atmosphere, and a specified electrical potential of 0 volts for the reference electrode. It is represented by the symbol E°.
The standard potential is measured relative to the standard hydrogen electrode (SHE), which is assigned a value of 0 volts at all temperatures. The standard hydrogen electrode consists of a platinum electrode immersed in a solution of 1 molar HCl, with a stream of hydrogen gas bubbling through it. The electrode serves as a reference point to determine the reduction potentials of other half-cells.
If the standard potential of a half-cell is positive, it indicates that the half-cell is likely to undergo reduction, while a negative value suggests a tendency towards oxidation. The standard potential can be used to calculate the electromotive force (EMF) of a whole cell, which represents the potential difference between the two half-cells in an electrochemical system.
In summary, the standard potential is a reference point used to compare and predict the behavior of electrochemical reactions. It quantifies the electrode's tendency to gain or lose electrons and is measured relative to the standard hydrogen electrode under standardized conditions.
Etymology of STANDARD POTENTIAL
The etymology of the word "standard potential" comes from the combination of two terms: "standard" and "potential".
The word "standard" originated from the Old French word "estandard" which referred to a flag or banner used as a rallying point. It later developed to mean a generally accepted measure or model that serves as a reference point for comparison. In the context of "standard potential", it signifies the agreed-upon reference value or fixed condition.
The term "potential" traces back to the Latin word "potentialis", which means "possible" or "capable". It stems from the Latin verb "posse", meaning "to be able" or "to have power". In the case of "standard potential", it refers to the electrical potential or voltage at a specific condition or state.
