Ecell equation

[806018033]

When do we use, ln Q rather than logQ

[905934067]

In the context of the Nernst equation used to calculate the cell potential the natural logarithm (ln) is typically used when dealing with reactions involving the passage of electrons (i.e., electrochemical reactions) and where the reaction quotient (Q) is expressed in terms of concentrations. This is because ln is the natural logarithm function, which is mathematically suitable for dealing with exponential decay or growth, which is often observed in electrochemical systems. On the other hand, when dealing with reactions where Q is expressed in terms of base 10 logarithm of concentrations (i.e., pH in acid-base reactions), the base 10 logarithm (log) is used. The choice between ln and log depends on the nature of the system and the units used to express the reaction quotient.

[Jolene Robles 2H]

You use lnQ when you are using the nernst equation and calculating cell potential under non standard conditions. You used logQ when you the question says anything about ph scale. You used logQ to find the concentration of hydrogen ions (H+) or hydroxide ions (OH-).