can someone explain this to me, looking at graphs in my textbook, it seems as concentration increases the electric potential goes down? why is this? wouldn't you suspect that as the more concentrated a solution is the greater the electric potential read?
Concentrations that affect electrochemical galvanic potentials are defined in terms of concentrations of ions undergoing oxidation and reduction in their respective cells. That is, when a battery is new, the concentration of ions in solution at the anode (oxidation cell) will be very low and the conc of ions in solution at the cathode will be very high (reduction cell). As the battery discharges, the concentration of ions in the anodic cell increases while the concentration of ions in the cathodic cell decreases. The variation of concentrations is applied to the Nernst Equation to determine the voltage as a function of changing anodic and cathodic cell ion concentrations. E(non-std) = E(std) + RTln([anodic ion conc]/[cathodic ion conc])
thanks mate, i appreciate it
The relationship between concentration and electric potential can be better understood by considering the concept of ions and their behavior in a solution. Ions are charged particles that can carry electric charge, and their movement in a solution plays a key role in determining the electric potential.
When a solution is more concentrated, it means that there are more ions present in a given volume. In other words, there is a higher ion density. This increased concentration leads to more opportunities for interaction and collisions between the ions.
As ions collide with each other, they experience a certain level of resistance or friction. This resistance increases as the concentration rises because there are more frequent collisions happening. The collisions disrupt the flow of charge and impede the movement of ions.
As a result of these collisions, the overall mobility or ability for ions to move freely decreases. When the mobility decreases, the ions are less able to distribute themselves evenly across the solution. This uneven distribution leads to an electric potential difference or voltage across the solution.
In simpler terms, the increased concentration leads to more collisions and decreased ion mobility, which results in an uneven distribution of ions and a lower electric potential.
So, contrary to intuition, a higher concentration does not necessarily mean a higher electric potential. The relationship between concentration and electric potential is inversely proportional because the collisions and resistance caused by increased ion density negatively affect the overall movement of ions and the resulting electric potential.