52. Solution to Chemistry Problem

4. Calculate the pH of an aqueous solution if at a temperature of 25 C the potential difference between the quinhydrone and normal calomel (In.KCl) electrodes immersed in an acidic solution is 0.149 V. When solving, assume that in acidic solutions [C6H4O2]=[C6H4(OH)2] and the quinhydrone electrode with the reversible system
C6H4(OH)2=C6H4O2 2H 2e- behaves like a hydrogen electrode. At t=25 C E0quin.\hydr-KNKE=0.416 V.