Quinhydrone is a sparingly soluble one to one addition

Last updated: 7/4/2023

Quinhydrone is a sparingly soluble one to one addition compound formed from hydroquinone and quinone When solid quinhydrone is dissolved in an aqueous medium equal concentrations of hydroquinone and quinone result If a platinum wire is dipped into the solution the potential of the electrode is governed by the reversible reaction 2H 2e OH OH H Q Where Q denotes quinone and H Q denotes hydroquinone The E value of this half cell reaction is 0 46V with respect to the saturated calomel reference electrode SCE Because the potential of the quinine hydroquinone half reaction depends on the concentration of hydrogen ion it is possible to use this system to measure pH A sample solution of unknown pH was saturated with quinohydrone and a platinum electrode was dipped into it If the potential of the such electrode was found to be 0 22V with respect to SCE what was the PH of the sample solution 2 303 RT Given 0 06 F