Nernst equation
Have students memorize the Nernst equation, which is the most important in electrochemistry.
In a half-reaction in which substances A and B react with a molar ratio of a and b, and substances X and Y are produced with a molar ratio of x and y, the amount of electron transfer is n・e−. The concentration of substance A is expressed as [A], etc.
half reaction formula： a・A + b・B + n・e－ = x・X + y・Y
Potential generated in half reaction(E)
E = E0 － RT/(nF)・Ln{([X]x・[Y]y)
/ ([A]a・[B]b)}
E0 is the standard electrode potential, R is the gas constant, T is the temperature, and F is the Faraday constant
E is called the redox potential.
In addition,
When ([X]x・[Y]y) / ([A]a・[B]b) = 1, E = E0.
The standard electrode potential found earlier was a special solution of the Nernst equation.
In a general reaction system, ([X]x・[Y]y) / ([A]a・[B]b) = 1 is not necessarily the case, but any concentration ratio will be taken. This is the formula to find the redox potential in such a case. In the next course, we will solve example problems using the Nernst equation.
