![]() ![]() ![]() The flow must be such that it reduced the Cu 2+ concentration in the concentrated solution and thus increases it in the dilute solution: Instead, it is the electron flow that will balance the concentrations. In the electrochemical cell, the solutions are not in immediate contact so the ions cannot mix. An analogy would be mixing two solutions of CuSO 4 with different concentrations – at the end the solution will be of intermediate equal concentrations. The answer to this question is the tendency of the system to establish an equilibrium by making the concentration of Cu 2+ ions equal in both cells. So, how can we predict which direction the electron flow is going to be? Well, first of all, how do we know that there is going to be electron flow which would only happen if there were an overall cell potential? Let’s suppose we have an electrochemical cell made of copper electrodes merged in CuSO 4 solutions of different concentrations – suppose 0.10 M and 2.0 M: Now, here is a question: can we construct a Galvanic cell using identical electrodes for the anode and cathode and simply rely on the difference in the concentrations? And the answer is yes, even though having identical electrodes would mean the E o cell is zero, the E cell will still be greater than zero because of different concentrations. Q = K Reaction is already at equilibrium.Q K Reaction tends to form more reactants.The driving force here is that the system always tries to reach an equilibrium where Q becomes equal to K:įeel free to review the concept of reaction quotient and equilibrium constant by clicking on the highlighted sections, but here is the summary of what we need to know about Q and the direction of the equilibrium: Reaction quotient, Q tells us whether the forward or reverse reactions are going to be favorable based on the given concentrations of the reactants and products. Where E o is the cell potential under standard conditions, n is the moles of the electrons in the half-reactions, and Q is the reaction quotient This is a cell under nonstandard conditions and its potential is calculated using the Nernst equation: We have seen in the previous post that the cell potential depends not only on the type of the metal but also on the concentration of their electrolyte solutions. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |