CHEMISTRY COMMUNITY

What is the difference between E˚and E?

I believe E˚refers to standard conditions and E refers to nonstandard conditions.

Hi! The E nautical (with the circle) means E at standard conditions. The E, however, is just the cell potential in general under any conditions.

E˚ means that it is under standard condition which is T=298K and P=1 atm. E would then be the cell potential at a different temperature and or pressure. We can assume standard condition unless stated otherwise.

E^o is constant for each reaction, since it represents the cell reaction under very specific conditions (the standard state, 1 atm pressure and 25 ^oC).
E can vary, even within the same cell, as different experimental conditions impact the result of the reaction.

E˚ is the standard electrode potential under standard conditions while E is the cell potential under other conditions

E˚ is the standard and E is in a specific reaction. E˚ does not change through a reaction because the element is in its most stable state but E changes as the reaction goes on because the element may change because its not in its most stable state.

E˚ is under standard conditions such as 1 atm and 298 K while E is under any other condition.

E and E°can be calculated by the formula E = E°- （RT/nF) lnQ.

E˚is under standard conditions (pressure=1 bar, concentration= 1 mol/L, etc.)

E˚ is standard conditions, and will be given to you on a formula sheet or in the question for many reactions. E is nonstandard and has to be calculated using data.

E naut is for standard conditions while E is for non standard conditions

E˚ refers to the cell potential of a cell at standard conditions (25 degrees celsius, 1 M and 1 atm) and so it is a constant value that is given and will not change. E refers to the cell potential of a cell at any time, whether or not it's at standard conditions.

E* refers to cell potential at standard conditions, it does NOT change with amount of substance. E is just the potential of the cell under ANY conditions.