The selectivity coefficient, K+,H+ , for a K+ ion-selective electrode is 0.00575 . When the electrode is placed into a 7.38×10−5 M K+ solution at pH 6.58 , the potential is −0.168 V vs. SCE. If the pH of the solution is lowered to 1.23 and the ionic strength is kept constant, what is the potential of the electrode? Assume =1 for the electrode.