Question

What is the difference between $ E $ and $ {{E}^{\circ }} $ in electrochemistry?

Answer 1

Hint :We know that at first look at the definition of electrode potential. When no current is drawn through the cell then the electrode potential is basically emf of the cell. Cell emf is the maximum potential difference between the two electrodes of a cell. Also, we use knots on anything for its standard value.

Complete Step By Step Answer:
Electrochemistry deals with the electrochemical cells and the electrode potential refers to the electromotive force of a cell. It appears at an interface between an electrode and electrolyte due to the transfer of charged species that are ions. Basically, the electrode potential is the tendency of an electrode to lose or gain electrons when it is in contact with the solution of its own ions. Electrode potential depends on the nature of the electrode, concentration of the ions, temperature. There are different types of electrode potential depending upon the nature of the metal to lose or gain electrons. Oxidation potential: when electrodes possess negative charge with respect to the solution and oxidation takes place. - Reduction potential: when electrode is positively charged and reduction occurs. In the electrochemical cell, the cathode and anode have some electrode potential independently and the di
In electrochemistry $ {{E}^{\circ }} $ is the standard electrode potential which is also defined as the value of standard EMF of a cell in which molar hydrogen under standard pressure is oxidized to solvated proton at the left hand electrode. Now for the difference between $ E $ and $ {{E}^{\circ }} $ is that, $ E $ electromotive force on the non-standard cell and $ {{E}^{\circ }} $ is the electromotive force for the standard cell and the relation between them is given below:
 $ E={{E}^{\circ }}-\dfrac{0.0257}{n}\ln Q $
Here $ n $ is the number of moles of electrons transferred in the reaction.

Note :
Remember that the difference between the emf and the potential difference should be kept in mind. These two things are not the same, a slight difference between the electrodes; the potential difference is the difference between any two points of a closed circuit.