The standard electrode potential of a half cell is measured under conditions of
- A. 1 molar solution, 298 K and 1 atmosphere pressure
- B. any concentration at 273 K
- C. 0.1 molar solution at 373 K
- D. pure water at room temperature
Explanation
Standard conditions fix the concentration of every solution at 1 molar, the pressure of any gas at 1 atmosphere and the temperature at 298 K, so that values from different laboratories can be compared. Departing from these conditions changes the measured potential, which the Nernst equation quantifies. Note that 298 K is 25 degrees Celsius, not the 273 K of standard temperature for gases.