pH and cell potential

[Chem_Mod]

Hi, why and how does increasing the pH of a solution increase the cell potential of a battery? Thanks.

[Chem_Mod]

Increasing the pH of a solution DOES NOT always increase the cell potential of a battery. You need to consider the Nernst's equation
. If a pH change in the cell result in a change in Q, then it will affect E_cell.

[604596531 2k]

like in the case of question 3 on the 2011 practice final i was wondering why the cell potential would increase if the pH increased since doesn't that make the pOH smaller and making the concentration of the OH smaller and making bigger Q and making it more -

[Jocelyn]

So since the pH increases the pOH decreases and the CONCENTRATION of OH- increases therefore making Q smaller so E is then increasing.

[Rachael_1H]

Why would the pOH decreasing cause the OH- concentration to increase? Wouldnt it decrease according to the equation pOH=-log[OH-]?

[KaylaH]

Why would the pOH decreasing cause the OH- concentration to increase? Wouldnt it decrease according to the equation pOH=-log[OH-]?

Because if pH is increased from 11 to 13 (just for example), that means that pOH would decrease to 1. This means [OH-]=10^-1. If you plug this new value in for the concentration of OH- and solve for E, you will get a greater cell potential.